[PATCH 00/14] PEBS and LBR support

[PATCH 00/14] PEBS and LBR support

[Peter Zijlstra]

Simple PEBS and LBR support for perf, this seems to work on the one
machine I tested it on (nehalem class).

-- 

[PATCH 01/14] perf, x86: Remove superfluous arguments to x86_perf_event_set_period()

[Peter Zijlstra]

[-- Attachment #1: perf-x86-cleanup-args.patch --]
[-- Type: text/plain, Size: 2731 bytes --]

The second and third argument to x86_perf_event_set_period() are
superfluous since they are simple expressions of the first argument.
Hence remove them.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c       |   15 +++++++--------
 arch/x86/kernel/cpu/perf_event_intel.c |    2 +-
 2 files changed, 8 insertions(+), 9 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -165,8 +165,7 @@ static DEFINE_PER_CPU(struct cpu_hw_even
 	.enabled = 1,
 };
 
-static int x86_perf_event_set_period(struct perf_event *event,
-			     struct hw_perf_event *hwc, int idx);
+static int x86_perf_event_set_period(struct perf_event *event);
 
 /*
  * Generalized hw caching related hw_event table, filled
@@ -830,7 +829,7 @@ void hw_perf_enable(void)
 
 			if (hwc->idx == -1) {
 				x86_assign_hw_event(event, cpuc, i);
-				x86_perf_event_set_period(event, hwc, hwc->idx);
+				x86_perf_event_set_period(event);
 			}
 			/*
 			 * need to mark as active because x86_pmu_disable()
@@ -871,12 +870,12 @@ static DEFINE_PER_CPU(u64 [X86_PMC_IDX_M
  * To be called with the event disabled in hw:
  */
 static int
-x86_perf_event_set_period(struct perf_event *event,
-			     struct hw_perf_event *hwc, int idx)
+x86_perf_event_set_period(struct perf_event *event)
 {
+	struct hw_perf_event *hwc = &event->hw;
 	s64 left = atomic64_read(&hwc->period_left);
 	s64 period = hwc->sample_period;
-	int err, ret = 0;
+	int err, ret = 0, idx = hwc->idx;
 
 	if (idx == X86_PMC_IDX_FIXED_BTS)
 		return 0;
@@ -974,7 +973,7 @@ static int x86_pmu_start(struct perf_eve
 	if (hwc->idx == -1)
 		return -EAGAIN;
 
-	x86_perf_event_set_period(event, hwc, hwc->idx);
+	x86_perf_event_set_period(event);
 	x86_pmu.enable(hwc, hwc->idx);
 
 	return 0;
@@ -1119,7 +1118,7 @@ static int x86_pmu_handle_irq(struct pt_
 		handled		= 1;
 		data.period	= event->hw.last_period;
 
-		if (!x86_perf_event_set_period(event, hwc, idx))
+		if (!x86_perf_event_set_period(event))
 			continue;
 
 		if (perf_event_overflow(event, 1, &data, regs))
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -700,7 +700,7 @@ static int intel_pmu_save_and_restart(st
 	int ret;
 
 	x86_perf_event_update(event, hwc, idx);
-	ret = x86_perf_event_set_period(event, hwc, idx);
+	ret = x86_perf_event_set_period(event);
 
 	return ret;
 }

-- 

[tip:perf/urgent] perf, x86: Remove superfluous arguments to x86_perf_event_set_period()

[tip-bot for Peter Zijlstra]

Commit-ID:  07088edb88164c2a2406cd2d9a7be19d8515214b
Gitweb:     http://git.kernel.org/tip/07088edb88164c2a2406cd2d9a7be19d8515214b
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 2 Mar 2010 20:16:01 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:22:27 +0100

perf, x86: Remove superfluous arguments to x86_perf_event_set_period()

The second and third argument to x86_perf_event_set_period() are
superfluous since they are simple expressions of the first argument.
Hence remove them.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.006500906@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c       |   15 +++++++--------
 arch/x86/kernel/cpu/perf_event_intel.c |    2 +-
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 585d560..fcf1788 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -170,8 +170,7 @@ static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = {
 	.enabled = 1,
 };
 
-static int x86_perf_event_set_period(struct perf_event *event,
-			     struct hw_perf_event *hwc, int idx);
+static int x86_perf_event_set_period(struct perf_event *event);
 
 /*
  * Generalized hw caching related hw_event table, filled
@@ -835,7 +834,7 @@ void hw_perf_enable(void)
 
 			if (hwc->idx == -1) {
 				x86_assign_hw_event(event, cpuc, i);
-				x86_perf_event_set_period(event, hwc, hwc->idx);
+				x86_perf_event_set_period(event);
 			}
 			/*
 			 * need to mark as active because x86_pmu_disable()
@@ -876,12 +875,12 @@ static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
  * To be called with the event disabled in hw:
  */
 static int
-x86_perf_event_set_period(struct perf_event *event,
-			     struct hw_perf_event *hwc, int idx)
+x86_perf_event_set_period(struct perf_event *event)
 {
+	struct hw_perf_event *hwc = &event->hw;
 	s64 left = atomic64_read(&hwc->period_left);
 	s64 period = hwc->sample_period;
-	int err, ret = 0;
+	int err, ret = 0, idx = hwc->idx;
 
 	if (idx == X86_PMC_IDX_FIXED_BTS)
 		return 0;
@@ -979,7 +978,7 @@ static int x86_pmu_start(struct perf_event *event)
 	if (hwc->idx == -1)
 		return -EAGAIN;
 
-	x86_perf_event_set_period(event, hwc, hwc->idx);
+	x86_perf_event_set_period(event);
 	x86_pmu.enable(hwc, hwc->idx);
 
 	return 0;
@@ -1123,7 +1122,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
 		handled		= 1;
 		data.period	= event->hw.last_period;
 
-		if (!x86_perf_event_set_period(event, hwc, idx))
+		if (!x86_perf_event_set_period(event))
 			continue;
 
 		if (perf_event_overflow(event, 1, &data, regs))
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index c582449..6dbdf91 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -699,7 +699,7 @@ static int intel_pmu_save_and_restart(struct perf_event *event)
 	int ret;
 
 	x86_perf_event_update(event, hwc, idx);
-	ret = x86_perf_event_set_period(event, hwc, idx);
+	ret = x86_perf_event_set_period(event);
 
 	return ret;
 }

[PATCH 02/14] perf, x86: Remove superfluous arguments to x86_perf_event_update()

[Peter Zijlstra]

[-- Attachment #1: perf-x86-cleanup-args1.patch --]
[-- Type: text/plain, Size: 2526 bytes --]

The second and third argument to x86_perf_event_update() are
superfluous since they are simple expressions of the first argument.
Hence remove them.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c       |   11 ++++++-----
 arch/x86/kernel/cpu/perf_event_intel.c |   10 ++--------
 2 files changed, 8 insertions(+), 13 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -188,11 +188,12 @@ static u64 __read_mostly hw_cache_event_
  * Returns the delta events processed.
  */
 static u64
-x86_perf_event_update(struct perf_event *event,
-			struct hw_perf_event *hwc, int idx)
+x86_perf_event_update(struct perf_event *event)
 {
+	struct hw_perf_event *hwc = &event->hw;
 	int shift = 64 - x86_pmu.event_bits;
 	u64 prev_raw_count, new_raw_count;
+	int idx = hwc->idx;
 	s64 delta;
 
 	if (idx == X86_PMC_IDX_FIXED_BTS)
@@ -1059,7 +1060,7 @@ static void x86_pmu_stop(struct perf_eve
 	 * Drain the remaining delta count out of a event
 	 * that we are disabling:
 	 */
-	x86_perf_event_update(event, hwc, idx);
+	x86_perf_event_update(event);
 
 	cpuc->events[idx] = NULL;
 }
@@ -1108,7 +1109,7 @@ static int x86_pmu_handle_irq(struct pt_
 		event = cpuc->events[idx];
 		hwc = &event->hw;
 
-		val = x86_perf_event_update(event, hwc, idx);
+		val = x86_perf_event_update(event);
 		if (val & (1ULL << (x86_pmu.event_bits - 1)))
 			continue;
 
@@ -1419,7 +1420,7 @@ void __init init_hw_perf_events(void)
 
 static inline void x86_pmu_read(struct perf_event *event)
 {
-	x86_perf_event_update(event, &event->hw, event->hw.idx);
+	x86_perf_event_update(event);
 }
 
 static const struct pmu pmu = {
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -695,14 +695,8 @@ static void intel_pmu_enable_event(struc
  */
 static int intel_pmu_save_and_restart(struct perf_event *event)
 {
-	struct hw_perf_event *hwc = &event->hw;
-	int idx = hwc->idx;
-	int ret;
-
-	x86_perf_event_update(event, hwc, idx);
-	ret = x86_perf_event_set_period(event);
-
-	return ret;
+	x86_perf_event_update(event);
+	return x86_perf_event_set_period(event);
 }
 
 static void intel_pmu_reset(void)

-- 

[tip:perf/urgent] perf, x86: Remove superfluous arguments to x86_perf_event_update()

[tip-bot for Peter Zijlstra]

Commit-ID:  cc2ad4ba8792b9d4ff893ae3b845d2c5a6206fc9
Gitweb:     http://git.kernel.org/tip/cc2ad4ba8792b9d4ff893ae3b845d2c5a6206fc9
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 2 Mar 2010 20:18:39 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:22:27 +0100

perf, x86: Remove superfluous arguments to x86_perf_event_update()

The second and third argument to x86_perf_event_update() are superfluous
since they are simple expressions of the first argument. Hence remove
them.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.089468871@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c       |   11 ++++++-----
 arch/x86/kernel/cpu/perf_event_intel.c |   10 ++--------
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index fcf1788..086127b 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -193,11 +193,12 @@ static u64 __read_mostly hw_cache_event_ids
  * Returns the delta events processed.
  */
 static u64
-x86_perf_event_update(struct perf_event *event,
-			struct hw_perf_event *hwc, int idx)
+x86_perf_event_update(struct perf_event *event)
 {
+	struct hw_perf_event *hwc = &event->hw;
 	int shift = 64 - x86_pmu.event_bits;
 	u64 prev_raw_count, new_raw_count;
+	int idx = hwc->idx;
 	s64 delta;
 
 	if (idx == X86_PMC_IDX_FIXED_BTS)
@@ -1064,7 +1065,7 @@ static void x86_pmu_stop(struct perf_event *event)
 	 * Drain the remaining delta count out of a event
 	 * that we are disabling:
 	 */
-	x86_perf_event_update(event, hwc, idx);
+	x86_perf_event_update(event);
 
 	cpuc->events[idx] = NULL;
 }
@@ -1112,7 +1113,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
 		event = cpuc->events[idx];
 		hwc = &event->hw;
 
-		val = x86_perf_event_update(event, hwc, idx);
+		val = x86_perf_event_update(event);
 		if (val & (1ULL << (x86_pmu.event_bits - 1)))
 			continue;
 
@@ -1458,7 +1459,7 @@ void __init init_hw_perf_events(void)
 
 static inline void x86_pmu_read(struct perf_event *event)
 {
-	x86_perf_event_update(event, &event->hw, event->hw.idx);
+	x86_perf_event_update(event);
 }
 
 static const struct pmu pmu = {
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 6dbdf91..a4c9f16 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -694,14 +694,8 @@ static void intel_pmu_enable_event(struct hw_perf_event *hwc, int idx)
  */
 static int intel_pmu_save_and_restart(struct perf_event *event)
 {
-	struct hw_perf_event *hwc = &event->hw;
-	int idx = hwc->idx;
-	int ret;
-
-	x86_perf_event_update(event, hwc, idx);
-	ret = x86_perf_event_set_period(event);
-
-	return ret;
+	x86_perf_event_update(event);
+	return x86_perf_event_set_period(event);
 }
 
 static void intel_pmu_reset(void)

[PATCH 03/14] perf, x86: Change x86_pmu.{enable,disable} calling convention

[Peter Zijlstra]

[-- Attachment #1: perf-x86-cleanup-args2.patch --]
[-- Type: text/plain, Size: 7280 bytes --]

Pass the full perf_event into the x86_pmu functions so that those may
make use of more than the hw_perf_event, and while doing this, remove
the superfluous second argument.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c       |   31 +++++++++++++++----------------
 arch/x86/kernel/cpu/perf_event_intel.c |   30 +++++++++++++++++-------------
 arch/x86/kernel/cpu/perf_event_p6.c    |   10 ++++++----
 3 files changed, 38 insertions(+), 33 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -133,8 +133,8 @@ struct x86_pmu {
 	int		(*handle_irq)(struct pt_regs *);
 	void		(*disable_all)(void);
 	void		(*enable_all)(void);
-	void		(*enable)(struct hw_perf_event *, int);
-	void		(*disable)(struct hw_perf_event *, int);
+	void		(*enable)(struct perf_event *);
+	void		(*disable)(struct perf_event *);
 	unsigned	eventsel;
 	unsigned	perfctr;
 	u64		(*event_map)(int);
@@ -840,7 +840,7 @@ void hw_perf_enable(void)
 			set_bit(hwc->idx, cpuc->active_mask);
 			cpuc->events[hwc->idx] = event;
 
-			x86_pmu.enable(hwc, hwc->idx);
+			x86_pmu.enable(event);
 			perf_event_update_userpage(event);
 		}
 		cpuc->n_added = 0;
@@ -853,15 +853,16 @@ void hw_perf_enable(void)
 	x86_pmu.enable_all();
 }
 
-static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc)
 {
-	(void)checking_wrmsrl(hwc->config_base + idx,
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx,
 			      hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE);
 }
 
-static inline void x86_pmu_disable_event(struct hw_perf_event *hwc, int idx)
+static inline void x86_pmu_disable_event(struct perf_event *event)
 {
-	(void)checking_wrmsrl(hwc->config_base + idx, hwc->config);
+	struct hw_perf_event *hwc = &event->hw;
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx, hwc->config);
 }
 
 static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
@@ -922,11 +923,11 @@ x86_perf_event_set_period(struct perf_ev
 	return ret;
 }
 
-static void x86_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void x86_pmu_enable_event(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 	if (cpuc->enabled)
-		__x86_pmu_enable_event(hwc, idx);
+		__x86_pmu_enable_event(&event->hw);
 }
 
 /*
@@ -969,13 +970,11 @@ static int x86_pmu_enable(struct perf_ev
 
 static int x86_pmu_start(struct perf_event *event)
 {
-	struct hw_perf_event *hwc = &event->hw;
-
-	if (hwc->idx == -1)
+	if (event->hw.idx == -1)
 		return -EAGAIN;
 
 	x86_perf_event_set_period(event);
-	x86_pmu.enable(hwc, hwc->idx);
+	x86_pmu.enable(event);
 
 	return 0;
 }
@@ -989,7 +988,7 @@ static void x86_pmu_unthrottle(struct pe
 				cpuc->events[hwc->idx] != event))
 		return;
 
-	x86_pmu.enable(hwc, hwc->idx);
+	x86_pmu.enable(event);
 }
 
 void perf_event_print_debug(void)
@@ -1054,7 +1053,7 @@ static void x86_pmu_stop(struct perf_eve
 	 * could reenable again:
 	 */
 	clear_bit(idx, cpuc->active_mask);
-	x86_pmu.disable(hwc, idx);
+	x86_pmu.disable(event);
 
 	/*
 	 * Drain the remaining delta count out of a event
@@ -1123,7 +1122,7 @@ static int x86_pmu_handle_irq(struct pt_
 			continue;
 
 		if (perf_event_overflow(event, 1, &data, regs))
-			x86_pmu.disable(hwc, idx);
+			x86_pmu.disable(event);
 	}
 
 	if (handled)
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -548,9 +548,9 @@ static inline void intel_pmu_ack_status(
 }
 
 static inline void
-intel_pmu_disable_fixed(struct hw_perf_event *hwc, int __idx)
+intel_pmu_disable_fixed(struct hw_perf_event *hwc)
 {
-	int idx = __idx - X86_PMC_IDX_FIXED;
+	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, mask;
 
 	mask = 0xfULL << (idx * 4);
@@ -622,26 +622,28 @@ static void intel_pmu_drain_bts_buffer(v
 }
 
 static inline void
-intel_pmu_disable_event(struct hw_perf_event *hwc, int idx)
+intel_pmu_disable_event(struct perf_event *event)
 {
-	if (unlikely(idx == X86_PMC_IDX_FIXED_BTS)) {
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (unlikely(hwc->idx == X86_PMC_IDX_FIXED_BTS)) {
 		intel_pmu_disable_bts();
 		intel_pmu_drain_bts_buffer();
 		return;
 	}
 
 	if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL)) {
-		intel_pmu_disable_fixed(hwc, idx);
+		intel_pmu_disable_fixed(hwc);
 		return;
 	}
 
-	x86_pmu_disable_event(hwc, idx);
+	x86_pmu_disable_event(event);
 }
 
 static inline void
-intel_pmu_enable_fixed(struct hw_perf_event *hwc, int __idx)
+intel_pmu_enable_fixed(struct hw_perf_event *hwc)
 {
-	int idx = __idx - X86_PMC_IDX_FIXED;
+	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, bits, mask;
 	int err;
 
@@ -671,9 +673,11 @@ intel_pmu_enable_fixed(struct hw_perf_ev
 	err = checking_wrmsrl(hwc->config_base, ctrl_val);
 }
 
-static void intel_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void intel_pmu_enable_event(struct perf_event *event)
 {
-	if (unlikely(idx == X86_PMC_IDX_FIXED_BTS)) {
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (unlikely(hwc->idx == X86_PMC_IDX_FIXED_BTS)) {
 		if (!__get_cpu_var(cpu_hw_events).enabled)
 			return;
 
@@ -682,11 +686,11 @@ static void intel_pmu_enable_event(struc
 	}
 
 	if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL)) {
-		intel_pmu_enable_fixed(hwc, idx);
+		intel_pmu_enable_fixed(hwc);
 		return;
 	}
 
-	__x86_pmu_enable_event(hwc, idx);
+	__x86_pmu_enable_event(hwc);
 }
 
 /*
@@ -774,7 +778,7 @@ again:
 		data.period = event->hw.last_period;
 
 		if (perf_event_overflow(event, 1, &data, regs))
-			intel_pmu_disable_event(&event->hw, bit);
+			intel_pmu_disable_event(event);
 	}
 
 	intel_pmu_ack_status(ack);
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_p6.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_p6.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_p6.c
@@ -77,27 +77,29 @@ static void p6_pmu_enable_all(void)
 }
 
 static inline void
-p6_pmu_disable_event(struct hw_perf_event *hwc, int idx)
+p6_pmu_disable_event(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val = P6_NOP_EVENT;
 
 	if (cpuc->enabled)
 		val |= ARCH_PERFMON_EVENTSEL_ENABLE;
 
-	(void)checking_wrmsrl(hwc->config_base + idx, val);
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx, val);
 }
 
-static void p6_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void p6_pmu_enable_event(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val;
 
 	val = hwc->config;
 	if (cpuc->enabled)
 		val |= ARCH_PERFMON_EVENTSEL_ENABLE;
 
-	(void)checking_wrmsrl(hwc->config_base + idx, val);
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx, val);
 }
 
 static __initconst struct x86_pmu p6_pmu = {

-- 

[tip:perf/urgent] perf, x86: Change x86_pmu.{enable,disable} calling convention

[tip-bot for Peter Zijlstra]

Commit-ID:  aff3d91a913c9ae0c2f56b65b27cbd00c7d27ee3
Gitweb:     http://git.kernel.org/tip/aff3d91a913c9ae0c2f56b65b27cbd00c7d27ee3
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 2 Mar 2010 20:32:08 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:22:28 +0100

perf, x86: Change x86_pmu.{enable,disable} calling convention

Pass the full perf_event into the x86_pmu functions so that those may
make use of more than the hw_perf_event, and while doing this, remove the
superfluous second argument.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.165166129@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c       |   31 +++++++++++++++----------------
 arch/x86/kernel/cpu/perf_event_intel.c |   30 +++++++++++++++++-------------
 arch/x86/kernel/cpu/perf_event_p6.c    |   10 ++++++----
 3 files changed, 38 insertions(+), 33 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 086127b..2dd704f 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -133,8 +133,8 @@ struct x86_pmu {
 	int		(*handle_irq)(struct pt_regs *);
 	void		(*disable_all)(void);
 	void		(*enable_all)(void);
-	void		(*enable)(struct hw_perf_event *, int);
-	void		(*disable)(struct hw_perf_event *, int);
+	void		(*enable)(struct perf_event *);
+	void		(*disable)(struct perf_event *);
 	unsigned	eventsel;
 	unsigned	perfctr;
 	u64		(*event_map)(int);
@@ -845,7 +845,7 @@ void hw_perf_enable(void)
 			set_bit(hwc->idx, cpuc->active_mask);
 			cpuc->events[hwc->idx] = event;
 
-			x86_pmu.enable(hwc, hwc->idx);
+			x86_pmu.enable(event);
 			perf_event_update_userpage(event);
 		}
 		cpuc->n_added = 0;
@@ -858,15 +858,16 @@ void hw_perf_enable(void)
 	x86_pmu.enable_all();
 }
 
-static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc)
 {
-	(void)checking_wrmsrl(hwc->config_base + idx,
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx,
 			      hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE);
 }
 
-static inline void x86_pmu_disable_event(struct hw_perf_event *hwc, int idx)
+static inline void x86_pmu_disable_event(struct perf_event *event)
 {
-	(void)checking_wrmsrl(hwc->config_base + idx, hwc->config);
+	struct hw_perf_event *hwc = &event->hw;
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx, hwc->config);
 }
 
 static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
@@ -927,11 +928,11 @@ x86_perf_event_set_period(struct perf_event *event)
 	return ret;
 }
 
-static void x86_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void x86_pmu_enable_event(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 	if (cpuc->enabled)
-		__x86_pmu_enable_event(hwc, idx);
+		__x86_pmu_enable_event(&event->hw);
 }
 
 /*
@@ -974,13 +975,11 @@ static int x86_pmu_enable(struct perf_event *event)
 
 static int x86_pmu_start(struct perf_event *event)
 {
-	struct hw_perf_event *hwc = &event->hw;
-
-	if (hwc->idx == -1)
+	if (event->hw.idx == -1)
 		return -EAGAIN;
 
 	x86_perf_event_set_period(event);
-	x86_pmu.enable(hwc, hwc->idx);
+	x86_pmu.enable(event);
 
 	return 0;
 }
@@ -994,7 +993,7 @@ static void x86_pmu_unthrottle(struct perf_event *event)
 				cpuc->events[hwc->idx] != event))
 		return;
 
-	x86_pmu.enable(hwc, hwc->idx);
+	x86_pmu.enable(event);
 }
 
 void perf_event_print_debug(void)
@@ -1059,7 +1058,7 @@ static void x86_pmu_stop(struct perf_event *event)
 	 * could reenable again:
 	 */
 	clear_bit(idx, cpuc->active_mask);
-	x86_pmu.disable(hwc, idx);
+	x86_pmu.disable(event);
 
 	/*
 	 * Drain the remaining delta count out of a event
@@ -1127,7 +1126,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
 			continue;
 
 		if (perf_event_overflow(event, 1, &data, regs))
-			x86_pmu.disable(hwc, idx);
+			x86_pmu.disable(event);
 	}
 
 	if (handled)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index a4c9f16..a840948 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -548,9 +548,9 @@ static inline void intel_pmu_ack_status(u64 ack)
 }
 
 static inline void
-intel_pmu_disable_fixed(struct hw_perf_event *hwc, int __idx)
+intel_pmu_disable_fixed(struct hw_perf_event *hwc)
 {
-	int idx = __idx - X86_PMC_IDX_FIXED;
+	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, mask;
 
 	mask = 0xfULL << (idx * 4);
@@ -621,26 +621,28 @@ static void intel_pmu_drain_bts_buffer(void)
 }
 
 static inline void
-intel_pmu_disable_event(struct hw_perf_event *hwc, int idx)
+intel_pmu_disable_event(struct perf_event *event)
 {
-	if (unlikely(idx == X86_PMC_IDX_FIXED_BTS)) {
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (unlikely(hwc->idx == X86_PMC_IDX_FIXED_BTS)) {
 		intel_pmu_disable_bts();
 		intel_pmu_drain_bts_buffer();
 		return;
 	}
 
 	if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL)) {
-		intel_pmu_disable_fixed(hwc, idx);
+		intel_pmu_disable_fixed(hwc);
 		return;
 	}
 
-	x86_pmu_disable_event(hwc, idx);
+	x86_pmu_disable_event(event);
 }
 
 static inline void
-intel_pmu_enable_fixed(struct hw_perf_event *hwc, int __idx)
+intel_pmu_enable_fixed(struct hw_perf_event *hwc)
 {
-	int idx = __idx - X86_PMC_IDX_FIXED;
+	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, bits, mask;
 	int err;
 
@@ -670,9 +672,11 @@ intel_pmu_enable_fixed(struct hw_perf_event *hwc, int __idx)
 	err = checking_wrmsrl(hwc->config_base, ctrl_val);
 }
 
-static void intel_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void intel_pmu_enable_event(struct perf_event *event)
 {
-	if (unlikely(idx == X86_PMC_IDX_FIXED_BTS)) {
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (unlikely(hwc->idx == X86_PMC_IDX_FIXED_BTS)) {
 		if (!__get_cpu_var(cpu_hw_events).enabled)
 			return;
 
@@ -681,11 +685,11 @@ static void intel_pmu_enable_event(struct hw_perf_event *hwc, int idx)
 	}
 
 	if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL)) {
-		intel_pmu_enable_fixed(hwc, idx);
+		intel_pmu_enable_fixed(hwc);
 		return;
 	}
 
-	__x86_pmu_enable_event(hwc, idx);
+	__x86_pmu_enable_event(hwc);
 }
 
 /*
@@ -771,7 +775,7 @@ again:
 		data.period = event->hw.last_period;
 
 		if (perf_event_overflow(event, 1, &data, regs))
-			intel_pmu_disable_event(&event->hw, bit);
+			intel_pmu_disable_event(event);
 	}
 
 	intel_pmu_ack_status(ack);
diff --git a/arch/x86/kernel/cpu/perf_event_p6.c b/arch/x86/kernel/cpu/perf_event_p6.c
index a4e67b9..a330485 100644
--- a/arch/x86/kernel/cpu/perf_event_p6.c
+++ b/arch/x86/kernel/cpu/perf_event_p6.c
@@ -77,27 +77,29 @@ static void p6_pmu_enable_all(void)
 }
 
 static inline void
-p6_pmu_disable_event(struct hw_perf_event *hwc, int idx)
+p6_pmu_disable_event(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val = P6_NOP_EVENT;
 
 	if (cpuc->enabled)
 		val |= ARCH_PERFMON_EVENTSEL_ENABLE;
 
-	(void)checking_wrmsrl(hwc->config_base + idx, val);
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx, val);
 }
 
-static void p6_pmu_enable_event(struct hw_perf_event *hwc, int idx)
+static void p6_pmu_enable_event(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val;
 
 	val = hwc->config;
 	if (cpuc->enabled)
 		val |= ARCH_PERFMON_EVENTSEL_ENABLE;
 
-	(void)checking_wrmsrl(hwc->config_base + idx, val);
+	(void)checking_wrmsrl(hwc->config_base + hwc->idx, val);
 }
 
 static __initconst struct x86_pmu p6_pmu = {

[PATCH 04/14] perf, x86: Use unlocked bitops

[Peter Zijlstra]

[-- Attachment #1: perf-x86-unlocked-bitops.patch --]
[-- Type: text/plain, Size: 2626 bytes --]

There is no concurrency on these variables, so don't use LOCK'ed ops.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c       |    8 ++++----
 arch/x86/kernel/cpu/perf_event_amd.c   |    2 +-
 arch/x86/kernel/cpu/perf_event_intel.c |    2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -638,7 +638,7 @@ static int x86_schedule_events(struct cp
 		if (test_bit(hwc->idx, used_mask))
 			break;
 
-		set_bit(hwc->idx, used_mask);
+		__set_bit(hwc->idx, used_mask);
 		if (assign)
 			assign[i] = hwc->idx;
 	}
@@ -687,7 +687,7 @@ static int x86_schedule_events(struct cp
 			if (j == X86_PMC_IDX_MAX)
 				break;
 
-			set_bit(j, used_mask);
+			__set_bit(j, used_mask);
 
 			if (assign)
 				assign[i] = j;
@@ -837,7 +837,7 @@ void hw_perf_enable(void)
 			 * clear active_mask and events[] yet it preserves
 			 * idx
 			 */
-			set_bit(hwc->idx, cpuc->active_mask);
+			__set_bit(hwc->idx, cpuc->active_mask);
 			cpuc->events[hwc->idx] = event;
 
 			x86_pmu.enable(event);
@@ -1052,7 +1052,7 @@ static void x86_pmu_stop(struct perf_eve
 	 * Must be done before we disable, otherwise the nmi handler
 	 * could reenable again:
 	 */
-	clear_bit(idx, cpuc->active_mask);
+	__clear_bit(idx, cpuc->active_mask);
 	x86_pmu.disable(event);
 
 	/*
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_amd.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c
@@ -309,7 +309,7 @@ static struct amd_nb *amd_alloc_nb(int c
 	 * initialize all possible NB constraints
 	 */
 	for (i = 0; i < x86_pmu.num_events; i++) {
-		set_bit(i, nb->event_constraints[i].idxmsk);
+		__set_bit(i, nb->event_constraints[i].idxmsk);
 		nb->event_constraints[i].weight = 1;
 	}
 	return nb;
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -768,7 +768,7 @@ again:
 	for_each_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
 		struct perf_event *event = cpuc->events[bit];
 
-		clear_bit(bit, (unsigned long *) &status);
+		__clear_bit(bit, (unsigned long *) &status);
 		if (!test_bit(bit, cpuc->active_mask))
 			continue;
 

-- 

[tip:perf/urgent] perf, x86: Use unlocked bitops

[tip-bot for Peter Zijlstra]

Commit-ID:  34538ee77b39a12702e0f4c3ed9e8fa2dd5eb92c
Gitweb:     http://git.kernel.org/tip/34538ee77b39a12702e0f4c3ed9e8fa2dd5eb92c
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 2 Mar 2010 21:16:55 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:22:29 +0100

perf, x86: Use unlocked bitops

There is no concurrency on these variables, so don't use LOCK'ed ops.

As to the intel_pmu_handle_irq() status bit clean, nobody uses that so
remove it all together.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100304140100.240023029@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c       |    8 ++++----
 arch/x86/kernel/cpu/perf_event_amd.c   |    2 +-
 arch/x86/kernel/cpu/perf_event_intel.c |    1 -
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 2dd704f..01b1667 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -643,7 +643,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 		if (test_bit(hwc->idx, used_mask))
 			break;
 
-		set_bit(hwc->idx, used_mask);
+		__set_bit(hwc->idx, used_mask);
 		if (assign)
 			assign[i] = hwc->idx;
 	}
@@ -692,7 +692,7 @@ static int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 			if (j == X86_PMC_IDX_MAX)
 				break;
 
-			set_bit(j, used_mask);
+			__set_bit(j, used_mask);
 
 			if (assign)
 				assign[i] = j;
@@ -842,7 +842,7 @@ void hw_perf_enable(void)
 			 * clear active_mask and events[] yet it preserves
 			 * idx
 			 */
-			set_bit(hwc->idx, cpuc->active_mask);
+			__set_bit(hwc->idx, cpuc->active_mask);
 			cpuc->events[hwc->idx] = event;
 
 			x86_pmu.enable(event);
@@ -1057,7 +1057,7 @@ static void x86_pmu_stop(struct perf_event *event)
 	 * Must be done before we disable, otherwise the nmi handler
 	 * could reenable again:
 	 */
-	clear_bit(idx, cpuc->active_mask);
+	__clear_bit(idx, cpuc->active_mask);
 	x86_pmu.disable(event);
 
 	/*
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 014528b..573458f 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -287,7 +287,7 @@ static struct amd_nb *amd_alloc_nb(int cpu, int nb_id)
 	 * initialize all possible NB constraints
 	 */
 	for (i = 0; i < x86_pmu.num_events; i++) {
-		set_bit(i, nb->event_constraints[i].idxmsk);
+		__set_bit(i, nb->event_constraints[i].idxmsk);
 		nb->event_constraints[i].weight = 1;
 	}
 	return nb;
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index a840948..d87421c 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -765,7 +765,6 @@ again:
 	for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
 		struct perf_event *event = cpuc->events[bit];
 
-		clear_bit(bit, (unsigned long *) &status);
 		if (!test_bit(bit, cpuc->active_mask))
 			continue;
 

[PATCH 05/14] perf: Generic perf_sample_data initialization

[Peter Zijlstra]

[-- Attachment #1: perf-fixup-data.patch --]
[-- Type: text/plain, Size: 6255 bytes --]

This makes it easier to extend perf_sample_data and fixes a bug on
arm and sparc, which failed to set ->raw to NULL, which can cause
crashes when combined with PERF_SAMPLE_RAW.

It also optimizes PowerPC and tracepoint, because the struct
initialization is forced to zero out the whole structure.

CC: Jamie Iles <jamie.iles@picochip.com>
CC: Jean Pihet <jpihet@mvista.com>
CC: Paul Mackerras <paulus@samba.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Stephane Eranian <eranian@google.com>
CC: stable@kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
---
 arch/arm/kernel/perf_event.c           |    4 ++--
 arch/powerpc/kernel/perf_event.c       |    8 ++++----
 arch/sparc/kernel/perf_event.c         |    2 +-
 arch/x86/kernel/cpu/perf_event.c       |    3 +--
 arch/x86/kernel/cpu/perf_event_intel.c |    6 ++----
 include/linux/perf_event.h             |    7 +++++++
 kernel/perf_event.c                    |   21 ++++++++-------------
 7 files changed, 25 insertions(+), 26 deletions(-)

Index: linux-2.6/arch/arm/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/arch/arm/kernel/perf_event.c
+++ linux-2.6/arch/arm/kernel/perf_event.c
@@ -965,7 +965,7 @@ armv6pmu_handle_irq(int irq_num,
 	 */
 	armv6_pmcr_write(pmcr);
 
-	data.addr = 0;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 	for (idx = 0; idx <= armpmu->num_events; ++idx) {
@@ -1945,7 +1945,7 @@ static irqreturn_t armv7pmu_handle_irq(i
 	 */
 	regs = get_irq_regs();
 
-	data.addr = 0;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 	for (idx = 0; idx <= armpmu->num_events; ++idx) {
Index: linux-2.6/arch/powerpc/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/perf_event.c
+++ linux-2.6/arch/powerpc/kernel/perf_event.c
@@ -1164,10 +1164,10 @@ static void record_and_restart(struct pe
 	 * Finally record data if requested.
 	 */
 	if (record) {
-		struct perf_sample_data data = {
-			.addr	= ~0ULL,
-			.period	= event->hw.last_period,
-		};
+		struct perf_sample_data data;
+
+		perf_sample_data_init(&data, ~0ULL);
+		data.period = event->hw.last_period;
 
 		if (event->attr.sample_type & PERF_SAMPLE_ADDR)
 			perf_get_data_addr(regs, &data.addr);
Index: linux-2.6/arch/sparc/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/arch/sparc/kernel/perf_event.c
+++ linux-2.6/arch/sparc/kernel/perf_event.c
@@ -1189,7 +1189,7 @@ static int __kprobes perf_event_nmi_hand
 
 	regs = args->regs;
 
-	data.addr = 0;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -1096,8 +1096,7 @@ static int x86_pmu_handle_irq(struct pt_
 	int idx, handled = 0;
 	u64 val;
 
-	data.addr = 0;
-	data.raw = NULL;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -590,10 +590,9 @@ static void intel_pmu_drain_bts_buffer(v
 
 	ds->bts_index = ds->bts_buffer_base;
 
+	perf_sample_data_init(&data, 0);
 
 	data.period	= event->hw.last_period;
-	data.addr	= 0;
-	data.raw	= NULL;
 	regs.ip		= 0;
 
 	/*
@@ -740,8 +739,7 @@ static int intel_pmu_handle_irq(struct p
 	int bit, loops;
 	u64 ack, status;
 
-	data.addr = 0;
-	data.raw = NULL;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -801,6 +801,13 @@ struct perf_sample_data {
 	struct perf_raw_record		*raw;
 };
 
+static inline
+void perf_sample_data_init(struct perf_sample_data *data, u64 addr)
+{
+	data->addr = addr;
+	data->raw  = NULL;
+}
+
 extern void perf_output_sample(struct perf_output_handle *handle,
 			       struct perf_event_header *header,
 			       struct perf_sample_data *data,
Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -4108,8 +4108,7 @@ void __perf_sw_event(u32 event_id, u64 n
 	if (rctx < 0)
 		return;
 
-	data.addr = addr;
-	data.raw  = NULL;
+	perf_sample_data_init(&data, addr);
 
 	do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs);
 
@@ -4154,11 +4153,10 @@ static enum hrtimer_restart perf_swevent
 	struct perf_event *event;
 	u64 period;
 
-	event	= container_of(hrtimer, struct perf_event, hw.hrtimer);
+	event = container_of(hrtimer, struct perf_event, hw.hrtimer);
 	event->pmu->read(event);
 
-	data.addr = 0;
-	data.raw = NULL;
+	perf_sample_data_init(&data, 0);
 	data.period = event->hw.last_period;
 	regs = get_irq_regs();
 	/*
@@ -4322,17 +4320,15 @@ static const struct pmu perf_ops_task_cl
 void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
 			  int entry_size)
 {
+	struct pt_regs *regs = get_irq_regs();
+	struct perf_sample_data data;
 	struct perf_raw_record raw = {
 		.size = entry_size,
 		.data = record,
 	};
 
-	struct perf_sample_data data = {
-		.addr = addr,
-		.raw = &raw,
-	};
-
-	struct pt_regs *regs = get_irq_regs();
+	perf_sample_data_init(&data, addr);
+	data.raw = &raw;
 
 	if (!regs)
 		regs = task_pt_regs(current);
@@ -4448,8 +4444,7 @@ void perf_bp_event(struct perf_event *bp
 	struct perf_sample_data sample;
 	struct pt_regs *regs = data;
 
-	sample.raw = NULL;
-	sample.addr = bp->attr.bp_addr;
+	perf_sample_data_init(&sample, bp->attr.bp_addr);
 
 	if (!perf_exclude_event(bp, regs))
 		perf_swevent_add(bp, 1, 1, &sample, regs);

-- 

[tip:perf/urgent] perf: Provide generic perf_sample_data initialization

[tip-bot for Peter Zijlstra]

Commit-ID:  dc1d628a67a8f042e711ea5accc0beedc3ef0092
Gitweb:     http://git.kernel.org/tip/dc1d628a67a8f042e711ea5accc0beedc3ef0092
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 3 Mar 2010 15:55:04 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:22:23 +0100

perf: Provide generic perf_sample_data initialization

This makes it easier to extend perf_sample_data and fixes a bug on arm
and sparc, which failed to set ->raw to NULL, which can cause crashes
when combined with PERF_SAMPLE_RAW.

It also optimizes PowerPC and tracepoint, because the struct
initialization is forced to zero out the whole structure.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jean Pihet <jpihet@mvista.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Jamie Iles <jamie.iles@picochip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: stable@kernel.org
LKML-Reference: <20100304140100.315416040@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/arm/kernel/perf_event.c           |    4 ++--
 arch/powerpc/kernel/perf_event.c       |    8 ++++----
 arch/sparc/kernel/perf_event.c         |    2 +-
 arch/x86/kernel/cpu/perf_event.c       |    3 +--
 arch/x86/kernel/cpu/perf_event_intel.c |    6 ++----
 include/linux/perf_event.h             |    7 +++++++
 kernel/perf_event.c                    |   21 ++++++++-------------
 7 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index c54ceb3..3875d99 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -965,7 +965,7 @@ armv6pmu_handle_irq(int irq_num,
 	 */
 	armv6_pmcr_write(pmcr);
 
-	data.addr = 0;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 	for (idx = 0; idx <= armpmu->num_events; ++idx) {
@@ -1945,7 +1945,7 @@ static irqreturn_t armv7pmu_handle_irq(int irq_num, void *dev)
 	 */
 	regs = get_irq_regs();
 
-	data.addr = 0;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 	for (idx = 0; idx <= armpmu->num_events; ++idx) {
diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index b6cf8f1..5120bd4 100644
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -1164,10 +1164,10 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
 	 * Finally record data if requested.
 	 */
 	if (record) {
-		struct perf_sample_data data = {
-			.addr	= ~0ULL,
-			.period	= event->hw.last_period,
-		};
+		struct perf_sample_data data;
+
+		perf_sample_data_init(&data, ~0ULL);
+		data.period = event->hw.last_period;
 
 		if (event->attr.sample_type & PERF_SAMPLE_ADDR)
 			perf_get_data_addr(regs, &data.addr);
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index 9f2b2ba..6504208 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1189,7 +1189,7 @@ static int __kprobes perf_event_nmi_handler(struct notifier_block *self,
 
 	regs = args->regs;
 
-	data.addr = 0;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 97cddbf..42aafd1 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1097,8 +1097,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
 	int idx, handled = 0;
 	u64 val;
 
-	data.addr = 0;
-	data.raw = NULL;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 73102df..44b60c8 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -590,10 +590,9 @@ static void intel_pmu_drain_bts_buffer(void)
 
 	ds->bts_index = ds->bts_buffer_base;
 
+	perf_sample_data_init(&data, 0);
 
 	data.period	= event->hw.last_period;
-	data.addr	= 0;
-	data.raw	= NULL;
 	regs.ip		= 0;
 
 	/*
@@ -742,8 +741,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
 	int bit, loops;
 	u64 ack, status;
 
-	data.addr = 0;
-	data.raw = NULL;
+	perf_sample_data_init(&data, 0);
 
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 90e0521..6f8cd7d 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -801,6 +801,13 @@ struct perf_sample_data {
 	struct perf_raw_record		*raw;
 };
 
+static inline
+void perf_sample_data_init(struct perf_sample_data *data, u64 addr)
+{
+	data->addr = addr;
+	data->raw  = NULL;
+}
+
 extern void perf_output_sample(struct perf_output_handle *handle,
 			       struct perf_event_header *header,
 			       struct perf_sample_data *data,
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index e687450..4393b9e 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4108,8 +4108,7 @@ void __perf_sw_event(u32 event_id, u64 nr, int nmi,
 	if (rctx < 0)
 		return;
 
-	data.addr = addr;
-	data.raw  = NULL;
+	perf_sample_data_init(&data, addr);
 
 	do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, &data, regs);
 
@@ -4154,11 +4153,10 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
 	struct perf_event *event;
 	u64 period;
 
-	event	= container_of(hrtimer, struct perf_event, hw.hrtimer);
+	event = container_of(hrtimer, struct perf_event, hw.hrtimer);
 	event->pmu->read(event);
 
-	data.addr = 0;
-	data.raw = NULL;
+	perf_sample_data_init(&data, 0);
 	data.period = event->hw.last_period;
 	regs = get_irq_regs();
 	/*
@@ -4322,17 +4320,15 @@ static const struct pmu perf_ops_task_clock = {
 void perf_tp_event(int event_id, u64 addr, u64 count, void *record,
 			  int entry_size)
 {
+	struct pt_regs *regs = get_irq_regs();
+	struct perf_sample_data data;
 	struct perf_raw_record raw = {
 		.size = entry_size,
 		.data = record,
 	};
 
-	struct perf_sample_data data = {
-		.addr = addr,
-		.raw = &raw,
-	};
-
-	struct pt_regs *regs = get_irq_regs();
+	perf_sample_data_init(&data, addr);
+	data.raw = &raw;
 
 	if (!regs)
 		regs = task_pt_regs(current);
@@ -4448,8 +4444,7 @@ void perf_bp_event(struct perf_event *bp, void *data)
 	struct perf_sample_data sample;
 	struct pt_regs *regs = data;
 
-	sample.raw = NULL;
-	sample.addr = bp->attr.bp_addr;
+	perf_sample_data_init(&sample, bp->attr.bp_addr);
 
 	if (!perf_exclude_event(bp, regs))
 		perf_swevent_add(bp, 1, 1, &sample, regs);

[PATCH 06/14] perf, x86: PEBS infrastructure

[Peter Zijlstra]

[-- Attachment #1: pebs.patch --]
[-- Type: text/plain, Size: 29662 bytes --]

Implement a simple PEBS model that always takes a single PEBS event at
a time. This is done so that the interaction with the rest of the
system is as expected (freq adjust, period randomization, lbr).

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c          |  223 ++++-------
 arch/x86/kernel/cpu/perf_event_intel.c    |  152 +-------
 arch/x86/kernel/cpu/perf_event_intel_ds.c |  567 ++++++++++++++++++++++++++++++
 include/linux/perf_event.h                |    3 
 4 files changed, 682 insertions(+), 263 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -0,0 +1,567 @@
+#ifdef CONFIG_CPU_SUP_INTEL
+
+/* The maximal number of PEBS events: */
+#define MAX_PEBS_EVENTS		4
+
+/* The size of a BTS record in bytes: */
+#define BTS_RECORD_SIZE		24
+
+#define BTS_BUFFER_SIZE		(PAGE_SIZE << 4)
+#define PEBS_BUFFER_SIZE	PAGE_SIZE
+
+/*
+ * pebs_record_32 for p4 and core not supported
+
+struct pebs_record_32 {
+	u32 flags, ip;
+	u32 ax, bc, cx, dx;
+	u32 si, di, bp, sp;
+};
+
+ */
+
+struct pebs_record_core {
+	u64 flags, ip;
+	u64 ax, bx, cx, dx;
+	u64 si, di, bp, sp;
+	u64 r8,  r9,  r10, r11;
+	u64 r12, r13, r14, r15;
+};
+
+struct pebs_record_nhm {
+	u64 flags, ip;
+	u64 ax, bx, cx, dx;
+	u64 si, di, bp, sp;
+	u64 r8,  r9,  r10, r11;
+	u64 r12, r13, r14, r15;
+	u64 status, dla, dse, lat;
+};
+
+/*
+ * Bits in the debugctlmsr controlling branch tracing.
+ */
+#define X86_DEBUGCTL_TR			(1 << 6)
+#define X86_DEBUGCTL_BTS		(1 << 7)
+#define X86_DEBUGCTL_BTINT		(1 << 8)
+#define X86_DEBUGCTL_BTS_OFF_OS		(1 << 9)
+#define X86_DEBUGCTL_BTS_OFF_USR	(1 << 10)
+
+/*
+ * A debug store configuration.
+ *
+ * We only support architectures that use 64bit fields.
+ */
+struct debug_store {
+	u64	bts_buffer_base;
+	u64	bts_index;
+	u64	bts_absolute_maximum;
+	u64	bts_interrupt_threshold;
+	u64	pebs_buffer_base;
+	u64	pebs_index;
+	u64	pebs_absolute_maximum;
+	u64	pebs_interrupt_threshold;
+	u64	pebs_event_reset[MAX_PEBS_EVENTS];
+};
+
+static inline void init_debug_store_on_cpu(int cpu)
+{
+	struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+	if (!ds)
+		return;
+
+	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
+		     (u32)((u64)(unsigned long)ds),
+		     (u32)((u64)(unsigned long)ds >> 32));
+}
+
+static inline void fini_debug_store_on_cpu(int cpu)
+{
+	if (!per_cpu(cpu_hw_events, cpu).ds)
+		return;
+
+	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
+}
+
+static void release_ds_buffers(void)
+{
+	int cpu;
+
+	if (!x86_pmu.bts && !x86_pmu.pebs)
+		return;
+
+	get_online_cpus();
+
+	for_each_online_cpu(cpu)
+		fini_debug_store_on_cpu(cpu);
+
+	for_each_possible_cpu(cpu) {
+		struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+		if (!ds)
+			continue;
+
+		per_cpu(cpu_hw_events, cpu).ds = NULL;
+
+		kfree((void *)(unsigned long)ds->pebs_buffer_base);
+		kfree((void *)(unsigned long)ds->bts_buffer_base);
+		kfree(ds);
+	}
+
+	put_online_cpus();
+}
+
+static int reserve_ds_buffers(void)
+{
+	int cpu, err = 0;
+
+	if (!x86_pmu.bts && !x86_pmu.pebs)
+		return 0;
+
+	get_online_cpus();
+
+	for_each_possible_cpu(cpu) {
+		struct debug_store *ds;
+		void *buffer;
+		int max, thresh;
+
+		err = -ENOMEM;
+		ds = kzalloc(sizeof(*ds), GFP_KERNEL);
+		if (unlikely(!ds)) {
+			kfree(buffer);
+			break;
+		}
+		per_cpu(cpu_hw_events, cpu).ds = ds;
+
+		if (x86_pmu.bts) {
+			buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
+			if (unlikely(!buffer))
+				break;
+
+			max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
+			thresh = max / 16;
+
+			ds->bts_buffer_base = (u64)(unsigned long)buffer;
+			ds->bts_index = ds->bts_buffer_base;
+			ds->bts_absolute_maximum = ds->bts_buffer_base +
+				max * BTS_RECORD_SIZE;
+			ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
+				thresh * BTS_RECORD_SIZE;
+		}
+
+		if (x86_pmu.pebs) {
+			buffer = kzalloc(PEBS_BUFFER_SIZE, GFP_KERNEL);
+			if (unlikely(!buffer))
+				break;
+
+			max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
+
+			ds->pebs_buffer_base = (u64)(unsigned long)buffer;
+			ds->pebs_index = ds->pebs_buffer_base;
+			ds->pebs_absolute_maximum = ds->pebs_buffer_base +
+				max * x86_pmu.pebs_record_size;
+			/*
+			 * Always use single record PEBS
+			 */
+			ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
+				x86_pmu.pebs_record_size;
+		}
+
+		err = 0;
+	}
+
+	if (err)
+		release_ds_buffers();
+	else {
+		for_each_online_cpu(cpu)
+			init_debug_store_on_cpu(cpu);
+	}
+
+	put_online_cpus();
+
+	return err;
+}
+
+/*
+ * BTS
+ */
+
+static struct event_constraint bts_constraint =
+	EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
+
+static void intel_pmu_enable_bts(u64 config)
+{
+	unsigned long debugctlmsr;
+
+	debugctlmsr = get_debugctlmsr();
+
+	debugctlmsr |= X86_DEBUGCTL_TR;
+	debugctlmsr |= X86_DEBUGCTL_BTS;
+	debugctlmsr |= X86_DEBUGCTL_BTINT;
+
+	if (!(config & ARCH_PERFMON_EVENTSEL_OS))
+		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_OS;
+
+	if (!(config & ARCH_PERFMON_EVENTSEL_USR))
+		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_USR;
+
+	update_debugctlmsr(debugctlmsr);
+}
+
+static void intel_pmu_disable_bts(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	unsigned long debugctlmsr;
+
+	if (!cpuc->ds)
+		return;
+
+	debugctlmsr = get_debugctlmsr();
+
+	debugctlmsr &=
+		~(X86_DEBUGCTL_TR | X86_DEBUGCTL_BTS | X86_DEBUGCTL_BTINT |
+		  X86_DEBUGCTL_BTS_OFF_OS | X86_DEBUGCTL_BTS_OFF_USR);
+
+	update_debugctlmsr(debugctlmsr);
+}
+
+static void intel_pmu_drain_bts_buffer(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct debug_store *ds = cpuc->ds;
+	struct bts_record {
+		u64	from;
+		u64	to;
+		u64	flags;
+	};
+	struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS];
+	struct bts_record *at, *top;
+	struct perf_output_handle handle;
+	struct perf_event_header header;
+	struct perf_sample_data data;
+	struct pt_regs regs;
+
+	if (!event)
+		return;
+
+	if (!ds)
+		return;
+
+	at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
+	top = (struct bts_record *)(unsigned long)ds->bts_index;
+
+	if (top <= at)
+		return;
+
+	ds->bts_index = ds->bts_buffer_base;
+
+	perf_sample_data_init(&data, 0);
+	data.period = event->hw.last_period;
+	regs.ip     = 0;
+
+	/*
+	 * Prepare a generic sample, i.e. fill in the invariant fields.
+	 * We will overwrite the from and to address before we output
+	 * the sample.
+	 */
+	perf_prepare_sample(&header, &data, event, &regs);
+
+	if (perf_output_begin(&handle, event, header.size * (top - at), 1, 1))
+		return;
+
+	for (; at < top; at++) {
+		data.ip		= at->from;
+		data.addr	= at->to;
+
+		perf_output_sample(&handle, &header, &data, event);
+	}
+
+	perf_output_end(&handle);
+
+	/* There's new data available. */
+	event->hw.interrupts++;
+	event->pending_kill = POLL_IN;
+}
+
+/*
+ * PEBS
+ */
+
+static struct event_constraint intel_core_pebs_events[] = {
+	PEBS_EVENT_CONSTRAINT(0x00c0, 0x1), /* INSTR_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0xfec1, 0x1), /* X87_OPS_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */
+	PEBS_EVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x01cb, 0x1), /* MEM_LOAD_RETIRED.L1D_MISS */
+	PEBS_EVENT_CONSTRAINT(0x02cb, 0x1), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x04cb, 0x1), /* MEM_LOAD_RETIRED.L2_MISS */
+	PEBS_EVENT_CONSTRAINT(0x08cb, 0x1), /* MEM_LOAD_RETIRED.L2_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x10cb, 0x1), /* MEM_LOAD_RETIRED.DTLB_MISS */
+	EVENT_CONSTRAINT_END
+};
+
+static struct event_constraint intel_nehalem_pebs_events[] = {
+	PEBS_EVENT_CONSTRAINT(0x00c0, 0xf), /* INSTR_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0xfec1, 0xf), /* X87_OPS_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x00c5, 0xf), /* BR_INST_RETIRED.MISPRED */
+	PEBS_EVENT_CONSTRAINT(0x1fc7, 0xf), /* SIMD_INST_RETURED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x01cb, 0xf), /* MEM_LOAD_RETIRED.L1D_MISS */
+	PEBS_EVENT_CONSTRAINT(0x02cb, 0xf), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x04cb, 0xf), /* MEM_LOAD_RETIRED.L2_MISS */
+	PEBS_EVENT_CONSTRAINT(0x08cb, 0xf), /* MEM_LOAD_RETIRED.L2_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x10cb, 0xf), /* MEM_LOAD_RETIRED.DTLB_MISS */
+	EVENT_CONSTRAINT_END
+};
+
+static struct event_constraint *
+intel_pebs_constraints(struct perf_event *event)
+{
+	struct event_constraint *c;
+
+	if (!event->attr.precise)
+		return NULL;
+
+	if (x86_pmu.pebs_constraints) {
+		for_each_event_constraint(c, x86_pmu.pebs_constraints) {
+			if ((event->hw.config & c->cmask) == c->code)
+				return c;
+		}
+	}
+
+	return &emptyconstraint;
+}
+
+static void intel_pmu_pebs_enable(struct hw_perf_event *hwc)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	u64 val = cpuc->pebs_enabled;
+
+	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
+
+	val |= 1ULL << hwc->idx;
+	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
+}
+
+static void intel_pmu_pebs_disable(struct hw_perf_event *hwc)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	u64 val = cpuc->pebs_enabled;
+
+	val &= ~(1ULL << hwc->idx);
+	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
+
+	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
+}
+
+static void intel_pmu_pebs_enable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->pebs_enabled)
+		wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
+}
+
+static void intel_pmu_pebs_disable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->pebs_enabled)
+		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
+}
+
+static int intel_pmu_save_and_restart(struct perf_event *event);
+static void intel_pmu_disable_event(struct perf_event *event);
+
+static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct debug_store *ds = cpuc->ds;
+	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
+	struct pebs_record_core *at, *top;
+	struct perf_sample_data data;
+	struct pt_regs regs;
+	int n;
+
+	if (!event || !ds || !x86_pmu.pebs)
+		return;
+
+	intel_pmu_pebs_disable_all();
+
+	at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
+	top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
+
+	if (top <= at)
+		goto out;
+
+	ds->pebs_index = ds->pebs_buffer_base;
+
+	if (!intel_pmu_save_and_restart(event))
+		goto out;
+
+	perf_sample_data_init(&data, 0);
+	data.period = event->hw.last_period;
+
+	n = top - at;
+
+	/*
+	 * Should not happen, we program the threshold at 1 and do not
+	 * set a reset value.
+	 */
+	if (unlikely(n > 1)) {
+		trace_printk("PEBS: too many events: %d\n", n);
+		at += n-1;
+	}
+
+	/*
+	 * We use the interrupt regs as a base because the PEBS record
+	 * does not contain a full regs set, specifically it seems to
+	 * lack segment descriptors, which get used by things like
+	 * user_mode().
+	 *
+	 * In the simple case fix up only the IP and BP,SP regs, for
+	 * PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly.
+	 * A possible PERF_SAMPLE_REGS will have to transfer all regs.
+	 */
+	regs = *iregs;
+	regs.ip = at->ip;
+	regs.bp = at->bp;
+	regs.sp = at->sp;
+
+	if (perf_event_overflow(event, 1, &data, &regs))
+		intel_pmu_disable_event(event);
+
+out:
+	intel_pmu_pebs_enable_all();
+}
+
+static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct debug_store *ds = cpuc->ds;
+	struct pebs_record_nhm *at, *top;
+	struct perf_sample_data data;
+	struct perf_event *event = NULL;
+	struct pt_regs regs;
+	int bit, n;
+
+	if (!ds || !x86_pmu.pebs)
+		return;
+
+	intel_pmu_pebs_disable_all();
+
+	at  = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
+	top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
+
+	if (top <= at)
+		goto out;
+
+	ds->pebs_index = ds->pebs_buffer_base;
+
+	n = top - at;
+
+	/*
+	 * Should not happen, we program the threshold at 1 and do not
+	 * set a reset value.
+	 */
+	if (unlikely(n > MAX_PEBS_EVENTS))
+		trace_printk("PEBS: too many events: %d\n", n);
+
+	for ( ; at < top; at++) {
+		for_each_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) {
+			if (!cpuc->events[bit]->attr.precise)
+				continue;
+
+			if (event)
+				trace_printk("PEBS: status: %Lx\n", at->status);
+
+			event = cpuc->events[bit];
+		}
+
+		if (!event) {
+			trace_printk("PEBS: interrupt, status: %Lx\n",
+					at->status);
+			continue;
+		}
+
+		if (!intel_pmu_save_and_restart(event))
+			continue;
+
+		perf_sample_data_init(&data, 0);
+		data.period = event->hw.last_period;
+
+		/*
+		 * See the comment in intel_pmu_drain_pebs_core()
+		 */
+		regs = *iregs;
+		regs.ip = at->ip;
+		regs.bp = at->bp;
+		regs.sp = at->sp;
+
+		if (perf_event_overflow(event, 1, &data, &regs))
+			intel_pmu_disable_event(event);
+	}
+out:
+	intel_pmu_pebs_enable_all();
+}
+
+/*
+ * BTS, PEBS probe and setup
+ */
+
+static void intel_ds_init(void)
+{
+	/*
+	 * No support for 32bit formats
+	 */
+	if (!boot_cpu_has(X86_FEATURE_DTES64))
+		return;
+
+	x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
+	x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
+	if (x86_pmu.pebs) {
+		int format = 0;
+
+		if (x86_pmu.version > 1) {
+			u64 capabilities;
+			/*
+			 * v2+ has a PEBS format field
+			 */
+			rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
+			format = (capabilities >> 8) & 0xf;
+		}
+
+		switch (format) {
+		case 0:
+			printk(KERN_CONT "PEBS v0, ");
+			x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
+			x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
+			x86_pmu.pebs_constraints = intel_core_pebs_events;
+			break;
+
+		case 1:
+			printk(KERN_CONT "PEBS v1, ");
+			x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
+			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
+			x86_pmu.pebs_constraints = intel_nehalem_pebs_events;
+			break;
+
+		default:
+			printk(KERN_CONT "PEBS unknown format: %d, ", format);
+			x86_pmu.pebs = 0;
+			break;
+		}
+	}
+}
+
+#else /* CONFIG_CPU_SUP_INTEL */
+
+static int reseve_ds_buffers(void)
+{
+	return 0;
+}
+
+static void release_ds_buffers(void)
+{
+}
+
+#endif /* CONFIG_CPU_SUP_INTEL */
Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -31,45 +31,6 @@
 
 static u64 perf_event_mask __read_mostly;
 
-/* The maximal number of PEBS events: */
-#define MAX_PEBS_EVENTS	4
-
-/* The size of a BTS record in bytes: */
-#define BTS_RECORD_SIZE		24
-
-/* The size of a per-cpu BTS buffer in bytes: */
-#define BTS_BUFFER_SIZE		(BTS_RECORD_SIZE * 2048)
-
-/* The BTS overflow threshold in bytes from the end of the buffer: */
-#define BTS_OVFL_TH		(BTS_RECORD_SIZE * 128)
-
-
-/*
- * Bits in the debugctlmsr controlling branch tracing.
- */
-#define X86_DEBUGCTL_TR			(1 << 6)
-#define X86_DEBUGCTL_BTS		(1 << 7)
-#define X86_DEBUGCTL_BTINT		(1 << 8)
-#define X86_DEBUGCTL_BTS_OFF_OS		(1 << 9)
-#define X86_DEBUGCTL_BTS_OFF_USR	(1 << 10)
-
-/*
- * A debug store configuration.
- *
- * We only support architectures that use 64bit fields.
- */
-struct debug_store {
-	u64	bts_buffer_base;
-	u64	bts_index;
-	u64	bts_absolute_maximum;
-	u64	bts_interrupt_threshold;
-	u64	pebs_buffer_base;
-	u64	pebs_index;
-	u64	pebs_absolute_maximum;
-	u64	pebs_interrupt_threshold;
-	u64	pebs_event_reset[MAX_PEBS_EVENTS];
-};
-
 struct event_constraint {
 	union {
 		unsigned long	idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
@@ -88,17 +49,29 @@ struct amd_nb {
 };
 
 struct cpu_hw_events {
+	/*
+	 * Generic x86 PMC bits
+	 */
 	struct perf_event	*events[X86_PMC_IDX_MAX]; /* in counter order */
 	unsigned long		active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 	unsigned long		interrupts;
 	int			enabled;
-	struct debug_store	*ds;
 
 	int			n_events;
 	int			n_added;
 	int			assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
 	u64			tags[X86_PMC_IDX_MAX];
 	struct perf_event	*event_list[X86_PMC_IDX_MAX]; /* in enabled order */
+
+	/*
+	 * Intel DebugStore bits
+	 */
+	struct debug_store	*ds;
+	u64			pebs_enabled;
+
+	/*
+	 * AMD specific bits
+	 */
 	struct amd_nb		*amd_nb;
 };
 
@@ -112,12 +85,24 @@ struct cpu_hw_events {
 #define EVENT_CONSTRAINT(c, n, m)	\
 	__EVENT_CONSTRAINT(c, n, m, HWEIGHT(n))
 
+/*
+ * Constraint on the Event code.
+ */
 #define INTEL_EVENT_CONSTRAINT(c, n)	\
 	EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVTSEL_MASK)
 
+/*
+ * Constraint on the Event code + UMask + fixed-mask
+ */
 #define FIXED_EVENT_CONSTRAINT(c, n)	\
 	EVENT_CONSTRAINT(c, (1ULL << (32+n)), INTEL_ARCH_FIXED_MASK)
 
+/*
+ * Constraint on the Event code + UMask
+ */
+#define PEBS_EVENT_CONSTRAINT(c, n)	\
+	EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK)
+
 #define EVENT_CONSTRAINT_END		\
 	EVENT_CONSTRAINT(0, 0, 0)
 
@@ -128,6 +113,9 @@ struct cpu_hw_events {
  * struct x86_pmu - generic x86 pmu
  */
 struct x86_pmu {
+	/*
+	 * Generic x86 PMC bits
+	 */
 	const char	*name;
 	int		version;
 	int		(*handle_irq)(struct pt_regs *);
@@ -146,10 +134,6 @@ struct x86_pmu {
 	u64		event_mask;
 	int		apic;
 	u64		max_period;
-	u64		intel_ctrl;
-	void		(*enable_bts)(u64 config);
-	void		(*disable_bts)(void);
-
 	struct event_constraint *
 			(*get_event_constraints)(struct cpu_hw_events *cpuc,
 						 struct perf_event *event);
@@ -157,6 +141,19 @@ struct x86_pmu {
 	void		(*put_event_constraints)(struct cpu_hw_events *cpuc,
 						 struct perf_event *event);
 	struct event_constraint *event_constraints;
+
+	/*
+	 * Intel Arch Perfmon v2+
+	 */
+	u64		intel_ctrl;
+
+	/*
+	 * Intel DebugStore bits
+	 */
+	int		bts, pebs;
+	int		pebs_record_size;
+	void		(*drain_pebs)(struct pt_regs *regs);
+	struct event_constraint *pebs_constraints;
 };
 
 static struct x86_pmu x86_pmu __read_mostly;
@@ -288,110 +285,14 @@ static void release_pmc_hardware(void)
 #endif
 }
 
-static inline bool bts_available(void)
-{
-	return x86_pmu.enable_bts != NULL;
-}
-
-static inline void init_debug_store_on_cpu(int cpu)
-{
-	struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
-
-	if (!ds)
-		return;
-
-	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
-		     (u32)((u64)(unsigned long)ds),
-		     (u32)((u64)(unsigned long)ds >> 32));
-}
-
-static inline void fini_debug_store_on_cpu(int cpu)
-{
-	if (!per_cpu(cpu_hw_events, cpu).ds)
-		return;
-
-	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
-}
-
-static void release_bts_hardware(void)
-{
-	int cpu;
-
-	if (!bts_available())
-		return;
-
-	get_online_cpus();
-
-	for_each_online_cpu(cpu)
-		fini_debug_store_on_cpu(cpu);
-
-	for_each_possible_cpu(cpu) {
-		struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
-
-		if (!ds)
-			continue;
-
-		per_cpu(cpu_hw_events, cpu).ds = NULL;
-
-		kfree((void *)(unsigned long)ds->bts_buffer_base);
-		kfree(ds);
-	}
-
-	put_online_cpus();
-}
-
-static int reserve_bts_hardware(void)
-{
-	int cpu, err = 0;
-
-	if (!bts_available())
-		return 0;
-
-	get_online_cpus();
-
-	for_each_possible_cpu(cpu) {
-		struct debug_store *ds;
-		void *buffer;
-
-		err = -ENOMEM;
-		buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
-		if (unlikely(!buffer))
-			break;
-
-		ds = kzalloc(sizeof(*ds), GFP_KERNEL);
-		if (unlikely(!ds)) {
-			kfree(buffer);
-			break;
-		}
-
-		ds->bts_buffer_base = (u64)(unsigned long)buffer;
-		ds->bts_index = ds->bts_buffer_base;
-		ds->bts_absolute_maximum =
-			ds->bts_buffer_base + BTS_BUFFER_SIZE;
-		ds->bts_interrupt_threshold =
-			ds->bts_absolute_maximum - BTS_OVFL_TH;
-
-		per_cpu(cpu_hw_events, cpu).ds = ds;
-		err = 0;
-	}
-
-	if (err)
-		release_bts_hardware();
-	else {
-		for_each_online_cpu(cpu)
-			init_debug_store_on_cpu(cpu);
-	}
-
-	put_online_cpus();
-
-	return err;
-}
+static int reserve_ds_buffers(void);
+static void release_ds_buffers(void);
 
 static void hw_perf_event_destroy(struct perf_event *event)
 {
 	if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) {
 		release_pmc_hardware();
-		release_bts_hardware();
+		release_ds_buffers();
 		mutex_unlock(&pmc_reserve_mutex);
 	}
 }
@@ -454,7 +355,7 @@ static int __hw_perf_event_init(struct p
 			if (!reserve_pmc_hardware())
 				err = -EBUSY;
 			else
-				err = reserve_bts_hardware();
+				err = reserve_ds_buffers();
 		}
 		if (!err)
 			atomic_inc(&active_events);
@@ -532,7 +433,7 @@ static int __hw_perf_event_init(struct p
 	if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) &&
 	    (hwc->sample_period == 1)) {
 		/* BTS is not supported by this architecture. */
-		if (!bts_available())
+		if (!x86_pmu.bts)
 			return -EOPNOTSUPP;
 
 		/* BTS is currently only allowed for user-mode. */
@@ -994,6 +895,7 @@ static void x86_pmu_unthrottle(struct pe
 void perf_event_print_debug(void)
 {
 	u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
+	u64 pebs;
 	struct cpu_hw_events *cpuc;
 	unsigned long flags;
 	int cpu, idx;
@@ -1011,12 +913,14 @@ void perf_event_print_debug(void)
 		rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
 		rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
 		rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
+		rdmsrl(MSR_IA32_PEBS_ENABLE, pebs);
 
 		pr_info("\n");
 		pr_info("CPU#%d: ctrl:       %016llx\n", cpu, ctrl);
 		pr_info("CPU#%d: status:     %016llx\n", cpu, status);
 		pr_info("CPU#%d: overflow:   %016llx\n", cpu, overflow);
 		pr_info("CPU#%d: fixed:      %016llx\n", cpu, fixed);
+		pr_info("CPU#%d: pebs:       %016llx\n", cpu, pebs);
 	}
 	pr_info("CPU#%d: active:       %016llx\n", cpu, *(u64 *)cpuc->active_mask);
 
@@ -1334,6 +1238,7 @@ undo:
 
 #include "perf_event_amd.c"
 #include "perf_event_p6.c"
+#include "perf_event_intel_ds.c"
 #include "perf_event_intel.c"
 
 static void __init pmu_check_apic(void)
@@ -1431,6 +1336,32 @@ static const struct pmu pmu = {
 };
 
 /*
+ * validate that we can schedule this event
+ */
+static int validate_event(struct perf_event *event)
+{
+	struct cpu_hw_events *fake_cpuc;
+	struct event_constraint *c;
+	int ret = 0;
+
+	fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
+	if (!fake_cpuc)
+		return -ENOMEM;
+
+	c = x86_pmu.get_event_constraints(fake_cpuc, event);
+
+	if (!c || !c->weight)
+		ret = -ENOSPC;
+
+	if (x86_pmu.put_event_constraints)
+		x86_pmu.put_event_constraints(fake_cpuc, event);
+
+	kfree(fake_cpuc);
+
+	return ret;
+}
+
+/*
  * validate a single event group
  *
  * validation include:
@@ -1495,6 +1426,8 @@ const struct pmu *hw_perf_event_init(str
 
 		if (event->group_leader != event)
 			err = validate_group(event);
+		else
+			err = validate_event(event);
 
 		event->pmu = tmp;
 	}
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -470,42 +470,6 @@ static u64 intel_pmu_raw_event(u64 hw_ev
 	return hw_event & CORE_EVNTSEL_MASK;
 }
 
-static void intel_pmu_enable_bts(u64 config)
-{
-	unsigned long debugctlmsr;
-
-	debugctlmsr = get_debugctlmsr();
-
-	debugctlmsr |= X86_DEBUGCTL_TR;
-	debugctlmsr |= X86_DEBUGCTL_BTS;
-	debugctlmsr |= X86_DEBUGCTL_BTINT;
-
-	if (!(config & ARCH_PERFMON_EVENTSEL_OS))
-		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_OS;
-
-	if (!(config & ARCH_PERFMON_EVENTSEL_USR))
-		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_USR;
-
-	update_debugctlmsr(debugctlmsr);
-}
-
-static void intel_pmu_disable_bts(void)
-{
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-	unsigned long debugctlmsr;
-
-	if (!cpuc->ds)
-		return;
-
-	debugctlmsr = get_debugctlmsr();
-
-	debugctlmsr &=
-		~(X86_DEBUGCTL_TR | X86_DEBUGCTL_BTS | X86_DEBUGCTL_BTINT |
-		  X86_DEBUGCTL_BTS_OFF_OS | X86_DEBUGCTL_BTS_OFF_USR);
-
-	update_debugctlmsr(debugctlmsr);
-}
-
 static void intel_pmu_disable_all(void)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -514,6 +478,8 @@ static void intel_pmu_disable_all(void)
 
 	if (test_bit(X86_PMC_IDX_FIXED_BTS, cpuc->active_mask))
 		intel_pmu_disable_bts();
+
+	intel_pmu_pebs_disable_all();
 }
 
 static void intel_pmu_enable_all(void)
@@ -531,6 +497,8 @@ static void intel_pmu_enable_all(void)
 
 		intel_pmu_enable_bts(event->hw.config);
 	}
+
+	intel_pmu_pebs_enable_all();
 }
 
 static inline u64 intel_pmu_get_status(void)
@@ -547,8 +515,7 @@ static inline void intel_pmu_ack_status(
 	wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack);
 }
 
-static inline void
-intel_pmu_disable_fixed(struct hw_perf_event *hwc)
+static void intel_pmu_disable_fixed(struct hw_perf_event *hwc)
 {
 	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, mask;
@@ -560,68 +527,7 @@ intel_pmu_disable_fixed(struct hw_perf_e
 	(void)checking_wrmsrl(hwc->config_base, ctrl_val);
 }
 
-static void intel_pmu_drain_bts_buffer(void)
-{
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-	struct debug_store *ds = cpuc->ds;
-	struct bts_record {
-		u64	from;
-		u64	to;
-		u64	flags;
-	};
-	struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS];
-	struct bts_record *at, *top;
-	struct perf_output_handle handle;
-	struct perf_event_header header;
-	struct perf_sample_data data;
-	struct pt_regs regs;
-
-	if (!event)
-		return;
-
-	if (!ds)
-		return;
-
-	at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
-	top = (struct bts_record *)(unsigned long)ds->bts_index;
-
-	if (top <= at)
-		return;
-
-	ds->bts_index = ds->bts_buffer_base;
-
-	perf_sample_data_init(&data, 0);
-
-	data.period	= event->hw.last_period;
-	regs.ip		= 0;
-
-	/*
-	 * Prepare a generic sample, i.e. fill in the invariant fields.
-	 * We will overwrite the from and to address before we output
-	 * the sample.
-	 */
-	perf_prepare_sample(&header, &data, event, &regs);
-
-	if (perf_output_begin(&handle, event,
-			      header.size * (top - at), 1, 1))
-		return;
-
-	for (; at < top; at++) {
-		data.ip		= at->from;
-		data.addr	= at->to;
-
-		perf_output_sample(&handle, &header, &data, event);
-	}
-
-	perf_output_end(&handle);
-
-	/* There's new data available. */
-	event->hw.interrupts++;
-	event->pending_kill = POLL_IN;
-}
-
-static inline void
-intel_pmu_disable_event(struct perf_event *event)
+static void intel_pmu_disable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
 
@@ -637,10 +543,12 @@ intel_pmu_disable_event(struct perf_even
 	}
 
 	x86_pmu_disable_event(event);
+
+	if (unlikely(event->attr.precise))
+		intel_pmu_pebs_disable(hwc);
 }
 
-static inline void
-intel_pmu_enable_fixed(struct hw_perf_event *hwc)
+static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
 {
 	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, bits, mask;
@@ -689,6 +597,9 @@ static void intel_pmu_enable_event(struc
 		return;
 	}
 
+	if (unlikely(event->attr.precise))
+		intel_pmu_pebs_enable(hwc);
+
 	__x86_pmu_enable_event(hwc);
 }
 
@@ -763,10 +674,17 @@ again:
 
 	inc_irq_stat(apic_perf_irqs);
 	ack = status;
+
+	/*
+	 * PEBS overflow sets bit 62 in the global status register
+	 */
+	if (__test_and_clear_bit(62, (unsigned long *)&status))
+		x86_pmu.drain_pebs(regs);
+
 	for_each_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
 		struct perf_event *event = cpuc->events[bit];
 
-		__clear_bit(bit, (unsigned long *) &status);
+		__clear_bit(bit, (unsigned long *)&status);
 		if (!test_bit(bit, cpuc->active_mask))
 			continue;
 
@@ -793,22 +711,18 @@ again:
 	return 1;
 }
 
-static struct event_constraint bts_constraint =
-	EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
-
 static struct event_constraint *
-intel_special_constraints(struct perf_event *event)
+intel_bts_constraints(struct perf_event *event)
 {
-	unsigned int hw_event;
-
-	hw_event = event->hw.config & INTEL_ARCH_EVENT_MASK;
+	struct hw_perf_event *hwc = &event->hw;
+	unsigned int hw_event, bts_event;
 
-	if (unlikely((hw_event ==
-		      x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS)) &&
-		     (event->hw.sample_period == 1))) {
+	hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
+	bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
 
+	if (unlikely(hw_event == bts_event && hwc->sample_period == 1))
 		return &bts_constraint;
-	}
+
 	return NULL;
 }
 
@@ -817,7 +731,11 @@ intel_get_event_constraints(struct cpu_h
 {
 	struct event_constraint *c;
 
-	c = intel_special_constraints(event);
+	c = intel_bts_constraints(event);
+	if (c)
+		return c;
+
+	c = intel_pebs_constraints(event);
 	if (c)
 		return c;
 
@@ -866,8 +784,6 @@ static __initconst struct x86_pmu intel_
 	 * the generic event period:
 	 */
 	.max_period		= (1ULL << 31) - 1,
-	.enable_bts		= intel_pmu_enable_bts,
-	.disable_bts		= intel_pmu_disable_bts,
 	.get_event_constraints	= intel_get_event_constraints
 };
 
@@ -914,6 +830,8 @@ static __init int intel_pmu_init(void)
 	if (version > 1)
 		x86_pmu.num_events_fixed = max((int)edx.split.num_events_fixed, 3);
 
+	intel_ds_init();
+
 	/*
 	 * Install the hw-cache-events table:
 	 */
Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -203,8 +203,9 @@ struct perf_event_attr {
 				enable_on_exec :  1, /* next exec enables     */
 				task           :  1, /* trace fork/exit       */
 				watermark      :  1, /* wakeup_watermark      */
+				precise        :  1, /* OoO invariant counter */
 
-				__reserved_1   : 49;
+				__reserved_1   : 48;
 
 	union {
 		__u32		wakeup_events;	  /* wakeup every n events */

-- 

Re: [PATCH 06/14] perf, x86: PEBS infrastructure

[Paul Mackerras]

On Thu, Mar 04, 2010 at 03:00:52PM +0100, Peter Zijlstra wrote:

> Implement a simple PEBS model that always takes a single PEBS event at
> a time. This is done so that the interaction with the rest of the
> system is as expected (freq adjust, period randomization, lbr).
> 
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> LKML-Reference: <new-submission>
> ---

...

> @@ -203,8 +203,9 @@ struct perf_event_attr {
>  				enable_on_exec :  1, /* next exec enables     */
>  				task           :  1, /* trace fork/exit       */
>  				watermark      :  1, /* wakeup_watermark      */
> +				precise        :  1, /* OoO invariant counter */

Could you explain in a bit more detail what this means?  

Also, it would be good to mention the ABI addition in the patch
description, and explain it briefly there.

Paul.

Re: [PATCH 06/14] perf, x86: PEBS infrastructure

[Peter Zijlstra]

On Fri, 2010-03-05 at 17:19 +1100, Paul Mackerras wrote:
> On Thu, Mar 04, 2010 at 03:00:52PM +0100, Peter Zijlstra wrote:
> 
> > Implement a simple PEBS model that always takes a single PEBS event at
> > a time. This is done so that the interaction with the rest of the
> > system is as expected (freq adjust, period randomization, lbr).
> > 
> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > LKML-Reference: <new-submission>
> > ---
> 
> ...
> 
> > @@ -203,8 +203,9 @@ struct perf_event_attr {
> >  				enable_on_exec :  1, /* next exec enables     */
> >  				task           :  1, /* trace fork/exit       */
> >  				watermark      :  1, /* wakeup_watermark      */
> > +				precise        :  1, /* OoO invariant counter */
> 
> Could you explain in a bit more detail what this means?  
> 
> Also, it would be good to mention the ABI addition in the patch
> description, and explain it briefly there.

Quite so, my bad.

So on Intel regular PMIs can happen several instructions later than the
actual event due to out-of-order processing of the instruction stream,
that is, it doesn't keep the IP of the actual instruction that triggered
the event, so all we have is the IP of where the interrupt happened (the
difference between these IPs is called skid).

Now Intel came up with something called Precise Event Based Sampling
(PEBS) which stores a (partial) register set in some memory buffer at
event time (trap like for some daft reason).

So from that we can obtain the IP of the instruction _after_ the
instruction that caused the event. This is reliably so (mostly [*]) and
does not contain out-of-order artifacts (0-skid).

So the ->precise flag tells us to use a more precise sampling method if
available on the hardware (AMD could be using IBS to implement this for
their instruction counter).

If you look at patch 9/14 you'll see we use the Last Branch Recording
(LBR) facility of the Intel cpus (patch 8/14) to find the last basic
block in the instruction stream and use that to rewind the instruction
stream to get the actual instruction that triggered the event. In case
that works I also set PERF_RECORD_MISC_EXACT to indicate we got the IP
dead on (mostly [*]).

I suspect CPUs that are strictly in-order, like Atom, might always have
it right, but I need to validate that.

Does that clarify stuff?

[*] there are CPU errata that may delay the PEBS recording, mostly with
instructions like MOV SS, STI and things like SMM.

Re: [PATCH 06/14] perf, x86: PEBS infrastructure

[Stephane Eranian]

On Fri, Mar 5, 2010 at 1:20 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, 2010-03-05 at 17:19 +1100, Paul Mackerras wrote:
>> On Thu, Mar 04, 2010 at 03:00:52PM +0100, Peter Zijlstra wrote:
>>
>> > Implement a simple PEBS model that always takes a single PEBS event at
>> > a time. This is done so that the interaction with the rest of the
>> > system is as expected (freq adjust, period randomization, lbr).
>> >
>> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
>> > LKML-Reference: <new-submission>
>> > ---
>>
>> ...
>>
>> > @@ -203,8 +203,9 @@ struct perf_event_attr {
>> >                             enable_on_exec :  1, /* next exec enables     */
>> >                             task           :  1, /* trace fork/exit       */
>> >                             watermark      :  1, /* wakeup_watermark      */
>> > +                           precise        :  1, /* OoO invariant counter */
>>
>> Could you explain in a bit more detail what this means?
>>
>> Also, it would be good to mention the ABI addition in the patch
>> description, and explain it briefly there.
>
> Quite so, my bad.
>
> So on Intel regular PMIs can happen several instructions later than the
> actual event due to out-of-order processing of the instruction stream,
> that is, it doesn't keep the IP of the actual instruction that triggered
> the event, so all we have is the IP of where the interrupt happened (the
> difference between these IPs is called skid).
>
I don't think the skid is strictly related to OoO. You had skid on Itanium
which was in-order.

> Now Intel came up with something called Precise Event Based Sampling
> (PEBS) which stores a (partial) register set in some memory buffer at
> event time (trap like for some daft reason).
>
> So from that we can obtain the IP of the instruction _after_ the
> instruction that caused the event. This is reliably so (mostly [*]) and
> does not contain out-of-order artifacts (0-skid).
>
The sampled instruction is guaranteed to have caused the event but
it is unrelated to your sampling period, i.e., it can be N events after
your sampling period due to the way PEBS is implemented.

> So the ->precise flag tells us to use a more precise sampling method if
> available on the hardware (AMD could be using IBS to implement this for
> their instruction counter).
>
> If you look at patch 9/14 you'll see we use the Last Branch Recording
> (LBR) facility of the Intel cpus (patch 8/14) to find the last basic
> block in the instruction stream and use that to rewind the instruction
> stream to get the actual instruction that triggered the event. In case
> that works I also set PERF_RECORD_MISC_EXACT to indicate we got the IP
> dead on (mostly [*]).
>
By rewinding you get the IP of the instruction that caused the event. But the
register state is STILL reflecting the situation at retirement of that
instruction.

> I suspect CPUs that are strictly in-order, like Atom, might always have
> it right, but I need to validate that.
>
Not sure about that.

Re: [PATCH 06/14] perf, x86: PEBS infrastructure

[Peter Zijlstra]

On Fri, 2010-03-05 at 11:11 -0800, Stephane Eranian wrote:
> By rewinding you get the IP of the instruction that caused the event. But the
> register state is STILL reflecting the situation at retirement of that
> instruction. 

I'm quite aware of that, but its near impossible to reverse interpret
instructions such as "mov rdx, $rdx", so until we get fault like PEBS
we'll just have to live with this.

Re: [PATCH 06/14] perf, x86: PEBS infrastructure

[Stephane Eranian]

On Fri, Mar 5, 2010 at 11:39 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, 2010-03-05 at 11:11 -0800, Stephane Eranian wrote:
>> By rewinding you get the IP of the instruction that caused the event. But the
>> register state is STILL reflecting the situation at retirement of that
>> instruction.
>
> I'm quite aware of that, but its near impossible to reverse interpret
> instructions such as "mov rdx, $rdx", so until we get fault like PEBS
> we'll just have to live with this.
>
I am sure you are, but that's not necessarily true of everybody.
So this needs to be clearly spelled out in some documentation
about precise + your MISC_EXACT bit.

[tip:perf/pebs] perf, x86: Add PEBS infrastructure

[tip-bot for Peter Zijlstra]

Commit-ID:  ca037701a025334e724e5c61b3b1082940c8b981
Gitweb:     http://git.kernel.org/tip/ca037701a025334e724e5c61b3b1082940c8b981
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 2 Mar 2010 19:52:12 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:31 +0100

perf, x86: Add PEBS infrastructure

This patch implements support for Intel Precise Event Based Sampling,
which is an alternative counter mode in which the counter triggers a
hardware assist to collect information on events. The hardware assist
takes a trap like snapshot of a subset of the machine registers.

This data is written to the Intel Debug-Store, which can be programmed
with a data threshold at which to raise a PMI.

With the PEBS hardware assist being trap like, the reported IP is always
one instruction after the actual instruction that triggered the event.

This implements a simple PEBS model that always takes a single PEBS event
at a time. This is done so that the interaction with the rest of the
system is as expected (freq adjust, period randomization, lbr,
callchains, etc.).

It adds an ABI element: perf_event_attr::precise, which indicates that we
wish to use this (constrained, but precise) mode.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.392111285@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c          |  223 ++++--------
 arch/x86/kernel/cpu/perf_event_intel.c    |  150 ++------
 arch/x86/kernel/cpu/perf_event_intel_ds.c |  557 +++++++++++++++++++++++++++++
 include/linux/perf_event.h                |    3 +-
 4 files changed, 671 insertions(+), 262 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 1d665a0..0c03d5c 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -31,45 +31,6 @@
 
 static u64 perf_event_mask __read_mostly;
 
-/* The maximal number of PEBS events: */
-#define MAX_PEBS_EVENTS	4
-
-/* The size of a BTS record in bytes: */
-#define BTS_RECORD_SIZE		24
-
-/* The size of a per-cpu BTS buffer in bytes: */
-#define BTS_BUFFER_SIZE		(BTS_RECORD_SIZE * 2048)
-
-/* The BTS overflow threshold in bytes from the end of the buffer: */
-#define BTS_OVFL_TH		(BTS_RECORD_SIZE * 128)
-
-
-/*
- * Bits in the debugctlmsr controlling branch tracing.
- */
-#define X86_DEBUGCTL_TR			(1 << 6)
-#define X86_DEBUGCTL_BTS		(1 << 7)
-#define X86_DEBUGCTL_BTINT		(1 << 8)
-#define X86_DEBUGCTL_BTS_OFF_OS		(1 << 9)
-#define X86_DEBUGCTL_BTS_OFF_USR	(1 << 10)
-
-/*
- * A debug store configuration.
- *
- * We only support architectures that use 64bit fields.
- */
-struct debug_store {
-	u64	bts_buffer_base;
-	u64	bts_index;
-	u64	bts_absolute_maximum;
-	u64	bts_interrupt_threshold;
-	u64	pebs_buffer_base;
-	u64	pebs_index;
-	u64	pebs_absolute_maximum;
-	u64	pebs_interrupt_threshold;
-	u64	pebs_event_reset[MAX_PEBS_EVENTS];
-};
-
 struct event_constraint {
 	union {
 		unsigned long	idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
@@ -88,17 +49,29 @@ struct amd_nb {
 };
 
 struct cpu_hw_events {
+	/*
+	 * Generic x86 PMC bits
+	 */
 	struct perf_event	*events[X86_PMC_IDX_MAX]; /* in counter order */
 	unsigned long		active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
 	unsigned long		interrupts;
 	int			enabled;
-	struct debug_store	*ds;
 
 	int			n_events;
 	int			n_added;
 	int			assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
 	u64			tags[X86_PMC_IDX_MAX];
 	struct perf_event	*event_list[X86_PMC_IDX_MAX]; /* in enabled order */
+
+	/*
+	 * Intel DebugStore bits
+	 */
+	struct debug_store	*ds;
+	u64			pebs_enabled;
+
+	/*
+	 * AMD specific bits
+	 */
 	struct amd_nb		*amd_nb;
 };
 
@@ -112,12 +85,24 @@ struct cpu_hw_events {
 #define EVENT_CONSTRAINT(c, n, m)	\
 	__EVENT_CONSTRAINT(c, n, m, HWEIGHT(n))
 
+/*
+ * Constraint on the Event code.
+ */
 #define INTEL_EVENT_CONSTRAINT(c, n)	\
 	EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVTSEL_MASK)
 
+/*
+ * Constraint on the Event code + UMask + fixed-mask
+ */
 #define FIXED_EVENT_CONSTRAINT(c, n)	\
 	EVENT_CONSTRAINT(c, (1ULL << (32+n)), INTEL_ARCH_FIXED_MASK)
 
+/*
+ * Constraint on the Event code + UMask
+ */
+#define PEBS_EVENT_CONSTRAINT(c, n)	\
+	EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK)
+
 #define EVENT_CONSTRAINT_END		\
 	EVENT_CONSTRAINT(0, 0, 0)
 
@@ -128,6 +113,9 @@ struct cpu_hw_events {
  * struct x86_pmu - generic x86 pmu
  */
 struct x86_pmu {
+	/*
+	 * Generic x86 PMC bits
+	 */
 	const char	*name;
 	int		version;
 	int		(*handle_irq)(struct pt_regs *);
@@ -146,10 +134,6 @@ struct x86_pmu {
 	u64		event_mask;
 	int		apic;
 	u64		max_period;
-	u64		intel_ctrl;
-	void		(*enable_bts)(u64 config);
-	void		(*disable_bts)(void);
-
 	struct event_constraint *
 			(*get_event_constraints)(struct cpu_hw_events *cpuc,
 						 struct perf_event *event);
@@ -162,6 +146,19 @@ struct x86_pmu {
 	void		(*cpu_starting)(int cpu);
 	void		(*cpu_dying)(int cpu);
 	void		(*cpu_dead)(int cpu);
+
+	/*
+	 * Intel Arch Perfmon v2+
+	 */
+	u64		intel_ctrl;
+
+	/*
+	 * Intel DebugStore bits
+	 */
+	int		bts, pebs;
+	int		pebs_record_size;
+	void		(*drain_pebs)(struct pt_regs *regs);
+	struct event_constraint *pebs_constraints;
 };
 
 static struct x86_pmu x86_pmu __read_mostly;
@@ -293,110 +290,14 @@ static void release_pmc_hardware(void)
 #endif
 }
 
-static inline bool bts_available(void)
-{
-	return x86_pmu.enable_bts != NULL;
-}
-
-static void init_debug_store_on_cpu(int cpu)
-{
-	struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
-
-	if (!ds)
-		return;
-
-	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
-		     (u32)((u64)(unsigned long)ds),
-		     (u32)((u64)(unsigned long)ds >> 32));
-}
-
-static void fini_debug_store_on_cpu(int cpu)
-{
-	if (!per_cpu(cpu_hw_events, cpu).ds)
-		return;
-
-	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
-}
-
-static void release_bts_hardware(void)
-{
-	int cpu;
-
-	if (!bts_available())
-		return;
-
-	get_online_cpus();
-
-	for_each_online_cpu(cpu)
-		fini_debug_store_on_cpu(cpu);
-
-	for_each_possible_cpu(cpu) {
-		struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
-
-		if (!ds)
-			continue;
-
-		per_cpu(cpu_hw_events, cpu).ds = NULL;
-
-		kfree((void *)(unsigned long)ds->bts_buffer_base);
-		kfree(ds);
-	}
-
-	put_online_cpus();
-}
-
-static int reserve_bts_hardware(void)
-{
-	int cpu, err = 0;
-
-	if (!bts_available())
-		return 0;
-
-	get_online_cpus();
-
-	for_each_possible_cpu(cpu) {
-		struct debug_store *ds;
-		void *buffer;
-
-		err = -ENOMEM;
-		buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
-		if (unlikely(!buffer))
-			break;
-
-		ds = kzalloc(sizeof(*ds), GFP_KERNEL);
-		if (unlikely(!ds)) {
-			kfree(buffer);
-			break;
-		}
-
-		ds->bts_buffer_base = (u64)(unsigned long)buffer;
-		ds->bts_index = ds->bts_buffer_base;
-		ds->bts_absolute_maximum =
-			ds->bts_buffer_base + BTS_BUFFER_SIZE;
-		ds->bts_interrupt_threshold =
-			ds->bts_absolute_maximum - BTS_OVFL_TH;
-
-		per_cpu(cpu_hw_events, cpu).ds = ds;
-		err = 0;
-	}
-
-	if (err)
-		release_bts_hardware();
-	else {
-		for_each_online_cpu(cpu)
-			init_debug_store_on_cpu(cpu);
-	}
-
-	put_online_cpus();
-
-	return err;
-}
+static int reserve_ds_buffers(void);
+static void release_ds_buffers(void);
 
 static void hw_perf_event_destroy(struct perf_event *event)
 {
 	if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) {
 		release_pmc_hardware();
-		release_bts_hardware();
+		release_ds_buffers();
 		mutex_unlock(&pmc_reserve_mutex);
 	}
 }
@@ -459,7 +360,7 @@ static int __hw_perf_event_init(struct perf_event *event)
 			if (!reserve_pmc_hardware())
 				err = -EBUSY;
 			else
-				err = reserve_bts_hardware();
+				err = reserve_ds_buffers();
 		}
 		if (!err)
 			atomic_inc(&active_events);
@@ -537,7 +438,7 @@ static int __hw_perf_event_init(struct perf_event *event)
 	if ((attr->config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) &&
 	    (hwc->sample_period == 1)) {
 		/* BTS is not supported by this architecture. */
-		if (!bts_available())
+		if (!x86_pmu.bts)
 			return -EOPNOTSUPP;
 
 		/* BTS is currently only allowed for user-mode. */
@@ -995,6 +896,7 @@ static void x86_pmu_unthrottle(struct perf_event *event)
 void perf_event_print_debug(void)
 {
 	u64 ctrl, status, overflow, pmc_ctrl, pmc_count, prev_left, fixed;
+	u64 pebs;
 	struct cpu_hw_events *cpuc;
 	unsigned long flags;
 	int cpu, idx;
@@ -1012,12 +914,14 @@ void perf_event_print_debug(void)
 		rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
 		rdmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, overflow);
 		rdmsrl(MSR_ARCH_PERFMON_FIXED_CTR_CTRL, fixed);
+		rdmsrl(MSR_IA32_PEBS_ENABLE, pebs);
 
 		pr_info("\n");
 		pr_info("CPU#%d: ctrl:       %016llx\n", cpu, ctrl);
 		pr_info("CPU#%d: status:     %016llx\n", cpu, status);
 		pr_info("CPU#%d: overflow:   %016llx\n", cpu, overflow);
 		pr_info("CPU#%d: fixed:      %016llx\n", cpu, fixed);
+		pr_info("CPU#%d: pebs:       %016llx\n", cpu, pebs);
 	}
 	pr_info("CPU#%d: active:       %016llx\n", cpu, *(u64 *)cpuc->active_mask);
 
@@ -1333,6 +1237,7 @@ undo:
 
 #include "perf_event_amd.c"
 #include "perf_event_p6.c"
+#include "perf_event_intel_ds.c"
 #include "perf_event_intel.c"
 
 static int __cpuinit
@@ -1465,6 +1370,32 @@ static const struct pmu pmu = {
 };
 
 /*
+ * validate that we can schedule this event
+ */
+static int validate_event(struct perf_event *event)
+{
+	struct cpu_hw_events *fake_cpuc;
+	struct event_constraint *c;
+	int ret = 0;
+
+	fake_cpuc = kmalloc(sizeof(*fake_cpuc), GFP_KERNEL | __GFP_ZERO);
+	if (!fake_cpuc)
+		return -ENOMEM;
+
+	c = x86_pmu.get_event_constraints(fake_cpuc, event);
+
+	if (!c || !c->weight)
+		ret = -ENOSPC;
+
+	if (x86_pmu.put_event_constraints)
+		x86_pmu.put_event_constraints(fake_cpuc, event);
+
+	kfree(fake_cpuc);
+
+	return ret;
+}
+
+/*
  * validate a single event group
  *
  * validation include:
@@ -1529,6 +1460,8 @@ const struct pmu *hw_perf_event_init(struct perf_event *event)
 
 		if (event->group_leader != event)
 			err = validate_group(event);
+		else
+			err = validate_event(event);
 
 		event->pmu = tmp;
 	}
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 84bfde6..1144641 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -470,42 +470,6 @@ static u64 intel_pmu_raw_event(u64 hw_event)
 	return hw_event & CORE_EVNTSEL_MASK;
 }
 
-static void intel_pmu_enable_bts(u64 config)
-{
-	unsigned long debugctlmsr;
-
-	debugctlmsr = get_debugctlmsr();
-
-	debugctlmsr |= X86_DEBUGCTL_TR;
-	debugctlmsr |= X86_DEBUGCTL_BTS;
-	debugctlmsr |= X86_DEBUGCTL_BTINT;
-
-	if (!(config & ARCH_PERFMON_EVENTSEL_OS))
-		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_OS;
-
-	if (!(config & ARCH_PERFMON_EVENTSEL_USR))
-		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_USR;
-
-	update_debugctlmsr(debugctlmsr);
-}
-
-static void intel_pmu_disable_bts(void)
-{
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-	unsigned long debugctlmsr;
-
-	if (!cpuc->ds)
-		return;
-
-	debugctlmsr = get_debugctlmsr();
-
-	debugctlmsr &=
-		~(X86_DEBUGCTL_TR | X86_DEBUGCTL_BTS | X86_DEBUGCTL_BTINT |
-		  X86_DEBUGCTL_BTS_OFF_OS | X86_DEBUGCTL_BTS_OFF_USR);
-
-	update_debugctlmsr(debugctlmsr);
-}
-
 static void intel_pmu_disable_all(void)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
@@ -514,6 +478,8 @@ static void intel_pmu_disable_all(void)
 
 	if (test_bit(X86_PMC_IDX_FIXED_BTS, cpuc->active_mask))
 		intel_pmu_disable_bts();
+
+	intel_pmu_pebs_disable_all();
 }
 
 static void intel_pmu_enable_all(void)
@@ -531,6 +497,8 @@ static void intel_pmu_enable_all(void)
 
 		intel_pmu_enable_bts(event->hw.config);
 	}
+
+	intel_pmu_pebs_enable_all();
 }
 
 static inline u64 intel_pmu_get_status(void)
@@ -547,8 +515,7 @@ static inline void intel_pmu_ack_status(u64 ack)
 	wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack);
 }
 
-static inline void
-intel_pmu_disable_fixed(struct hw_perf_event *hwc)
+static void intel_pmu_disable_fixed(struct hw_perf_event *hwc)
 {
 	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, mask;
@@ -560,68 +527,7 @@ intel_pmu_disable_fixed(struct hw_perf_event *hwc)
 	(void)checking_wrmsrl(hwc->config_base, ctrl_val);
 }
 
-static void intel_pmu_drain_bts_buffer(void)
-{
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-	struct debug_store *ds = cpuc->ds;
-	struct bts_record {
-		u64	from;
-		u64	to;
-		u64	flags;
-	};
-	struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS];
-	struct bts_record *at, *top;
-	struct perf_output_handle handle;
-	struct perf_event_header header;
-	struct perf_sample_data data;
-	struct pt_regs regs;
-
-	if (!event)
-		return;
-
-	if (!ds)
-		return;
-
-	at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
-	top = (struct bts_record *)(unsigned long)ds->bts_index;
-
-	if (top <= at)
-		return;
-
-	ds->bts_index = ds->bts_buffer_base;
-
-	perf_sample_data_init(&data, 0);
-
-	data.period	= event->hw.last_period;
-	regs.ip		= 0;
-
-	/*
-	 * Prepare a generic sample, i.e. fill in the invariant fields.
-	 * We will overwrite the from and to address before we output
-	 * the sample.
-	 */
-	perf_prepare_sample(&header, &data, event, &regs);
-
-	if (perf_output_begin(&handle, event,
-			      header.size * (top - at), 1, 1))
-		return;
-
-	for (; at < top; at++) {
-		data.ip		= at->from;
-		data.addr	= at->to;
-
-		perf_output_sample(&handle, &header, &data, event);
-	}
-
-	perf_output_end(&handle);
-
-	/* There's new data available. */
-	event->hw.interrupts++;
-	event->pending_kill = POLL_IN;
-}
-
-static inline void
-intel_pmu_disable_event(struct perf_event *event)
+static void intel_pmu_disable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
 
@@ -637,10 +543,12 @@ intel_pmu_disable_event(struct perf_event *event)
 	}
 
 	x86_pmu_disable_event(event);
+
+	if (unlikely(event->attr.precise))
+		intel_pmu_pebs_disable(hwc);
 }
 
-static inline void
-intel_pmu_enable_fixed(struct hw_perf_event *hwc)
+static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
 {
 	int idx = hwc->idx - X86_PMC_IDX_FIXED;
 	u64 ctrl_val, bits, mask;
@@ -689,6 +597,9 @@ static void intel_pmu_enable_event(struct perf_event *event)
 		return;
 	}
 
+	if (unlikely(event->attr.precise))
+		intel_pmu_pebs_enable(hwc);
+
 	__x86_pmu_enable_event(hwc);
 }
 
@@ -762,6 +673,13 @@ again:
 
 	inc_irq_stat(apic_perf_irqs);
 	ack = status;
+
+	/*
+	 * PEBS overflow sets bit 62 in the global status register
+	 */
+	if (__test_and_clear_bit(62, (unsigned long *)&status))
+		x86_pmu.drain_pebs(regs);
+
 	for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
 		struct perf_event *event = cpuc->events[bit];
 
@@ -791,22 +709,18 @@ done:
 	return 1;
 }
 
-static struct event_constraint bts_constraint =
-	EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
-
 static struct event_constraint *
-intel_special_constraints(struct perf_event *event)
+intel_bts_constraints(struct perf_event *event)
 {
-	unsigned int hw_event;
-
-	hw_event = event->hw.config & INTEL_ARCH_EVENT_MASK;
+	struct hw_perf_event *hwc = &event->hw;
+	unsigned int hw_event, bts_event;
 
-	if (unlikely((hw_event ==
-		      x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS)) &&
-		     (event->hw.sample_period == 1))) {
+	hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
+	bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
 
+	if (unlikely(hw_event == bts_event && hwc->sample_period == 1))
 		return &bts_constraint;
-	}
+
 	return NULL;
 }
 
@@ -815,7 +729,11 @@ intel_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event
 {
 	struct event_constraint *c;
 
-	c = intel_special_constraints(event);
+	c = intel_bts_constraints(event);
+	if (c)
+		return c;
+
+	c = intel_pebs_constraints(event);
 	if (c)
 		return c;
 
@@ -864,8 +782,6 @@ static __initconst struct x86_pmu intel_pmu = {
 	 * the generic event period:
 	 */
 	.max_period		= (1ULL << 31) - 1,
-	.enable_bts		= intel_pmu_enable_bts,
-	.disable_bts		= intel_pmu_disable_bts,
 	.get_event_constraints	= intel_get_event_constraints,
 
 	.cpu_starting		= init_debug_store_on_cpu,
@@ -915,6 +831,8 @@ static __init int intel_pmu_init(void)
 	if (version > 1)
 		x86_pmu.num_events_fixed = max((int)edx.split.num_events_fixed, 3);
 
+	intel_ds_init();
+
 	/*
 	 * Install the hw-cache-events table:
 	 */
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
new file mode 100644
index 0000000..0d994ef
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -0,0 +1,557 @@
+#ifdef CONFIG_CPU_SUP_INTEL
+
+/* The maximal number of PEBS events: */
+#define MAX_PEBS_EVENTS		4
+
+/* The size of a BTS record in bytes: */
+#define BTS_RECORD_SIZE		24
+
+#define BTS_BUFFER_SIZE		(PAGE_SIZE << 4)
+#define PEBS_BUFFER_SIZE	PAGE_SIZE
+
+/*
+ * pebs_record_32 for p4 and core not supported
+
+struct pebs_record_32 {
+	u32 flags, ip;
+	u32 ax, bc, cx, dx;
+	u32 si, di, bp, sp;
+};
+
+ */
+
+struct pebs_record_core {
+	u64 flags, ip;
+	u64 ax, bx, cx, dx;
+	u64 si, di, bp, sp;
+	u64 r8,  r9,  r10, r11;
+	u64 r12, r13, r14, r15;
+};
+
+struct pebs_record_nhm {
+	u64 flags, ip;
+	u64 ax, bx, cx, dx;
+	u64 si, di, bp, sp;
+	u64 r8,  r9,  r10, r11;
+	u64 r12, r13, r14, r15;
+	u64 status, dla, dse, lat;
+};
+
+/*
+ * Bits in the debugctlmsr controlling branch tracing.
+ */
+#define X86_DEBUGCTL_TR			(1 << 6)
+#define X86_DEBUGCTL_BTS		(1 << 7)
+#define X86_DEBUGCTL_BTINT		(1 << 8)
+#define X86_DEBUGCTL_BTS_OFF_OS		(1 << 9)
+#define X86_DEBUGCTL_BTS_OFF_USR	(1 << 10)
+
+/*
+ * A debug store configuration.
+ *
+ * We only support architectures that use 64bit fields.
+ */
+struct debug_store {
+	u64	bts_buffer_base;
+	u64	bts_index;
+	u64	bts_absolute_maximum;
+	u64	bts_interrupt_threshold;
+	u64	pebs_buffer_base;
+	u64	pebs_index;
+	u64	pebs_absolute_maximum;
+	u64	pebs_interrupt_threshold;
+	u64	pebs_event_reset[MAX_PEBS_EVENTS];
+};
+
+static void init_debug_store_on_cpu(int cpu)
+{
+	struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+	if (!ds)
+		return;
+
+	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
+		     (u32)((u64)(unsigned long)ds),
+		     (u32)((u64)(unsigned long)ds >> 32));
+}
+
+static void fini_debug_store_on_cpu(int cpu)
+{
+	if (!per_cpu(cpu_hw_events, cpu).ds)
+		return;
+
+	wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
+}
+
+static void release_ds_buffers(void)
+{
+	int cpu;
+
+	if (!x86_pmu.bts && !x86_pmu.pebs)
+		return;
+
+	get_online_cpus();
+
+	for_each_online_cpu(cpu)
+		fini_debug_store_on_cpu(cpu);
+
+	for_each_possible_cpu(cpu) {
+		struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+		if (!ds)
+			continue;
+
+		per_cpu(cpu_hw_events, cpu).ds = NULL;
+
+		kfree((void *)(unsigned long)ds->pebs_buffer_base);
+		kfree((void *)(unsigned long)ds->bts_buffer_base);
+		kfree(ds);
+	}
+
+	put_online_cpus();
+}
+
+static int reserve_ds_buffers(void)
+{
+	int cpu, err = 0;
+
+	if (!x86_pmu.bts && !x86_pmu.pebs)
+		return 0;
+
+	get_online_cpus();
+
+	for_each_possible_cpu(cpu) {
+		struct debug_store *ds;
+		void *buffer;
+		int max, thresh;
+
+		err = -ENOMEM;
+		ds = kzalloc(sizeof(*ds), GFP_KERNEL);
+		if (unlikely(!ds)) {
+			kfree(buffer);
+			break;
+		}
+		per_cpu(cpu_hw_events, cpu).ds = ds;
+
+		if (x86_pmu.bts) {
+			buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
+			if (unlikely(!buffer))
+				break;
+
+			max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
+			thresh = max / 16;
+
+			ds->bts_buffer_base = (u64)(unsigned long)buffer;
+			ds->bts_index = ds->bts_buffer_base;
+			ds->bts_absolute_maximum = ds->bts_buffer_base +
+				max * BTS_RECORD_SIZE;
+			ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
+				thresh * BTS_RECORD_SIZE;
+		}
+
+		if (x86_pmu.pebs) {
+			buffer = kzalloc(PEBS_BUFFER_SIZE, GFP_KERNEL);
+			if (unlikely(!buffer))
+				break;
+
+			max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
+
+			ds->pebs_buffer_base = (u64)(unsigned long)buffer;
+			ds->pebs_index = ds->pebs_buffer_base;
+			ds->pebs_absolute_maximum = ds->pebs_buffer_base +
+				max * x86_pmu.pebs_record_size;
+			/*
+			 * Always use single record PEBS
+			 */
+			ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
+				x86_pmu.pebs_record_size;
+		}
+
+		err = 0;
+	}
+
+	if (err)
+		release_ds_buffers();
+	else {
+		for_each_online_cpu(cpu)
+			init_debug_store_on_cpu(cpu);
+	}
+
+	put_online_cpus();
+
+	return err;
+}
+
+/*
+ * BTS
+ */
+
+static struct event_constraint bts_constraint =
+	EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
+
+static void intel_pmu_enable_bts(u64 config)
+{
+	unsigned long debugctlmsr;
+
+	debugctlmsr = get_debugctlmsr();
+
+	debugctlmsr |= X86_DEBUGCTL_TR;
+	debugctlmsr |= X86_DEBUGCTL_BTS;
+	debugctlmsr |= X86_DEBUGCTL_BTINT;
+
+	if (!(config & ARCH_PERFMON_EVENTSEL_OS))
+		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_OS;
+
+	if (!(config & ARCH_PERFMON_EVENTSEL_USR))
+		debugctlmsr |= X86_DEBUGCTL_BTS_OFF_USR;
+
+	update_debugctlmsr(debugctlmsr);
+}
+
+static void intel_pmu_disable_bts(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	unsigned long debugctlmsr;
+
+	if (!cpuc->ds)
+		return;
+
+	debugctlmsr = get_debugctlmsr();
+
+	debugctlmsr &=
+		~(X86_DEBUGCTL_TR | X86_DEBUGCTL_BTS | X86_DEBUGCTL_BTINT |
+		  X86_DEBUGCTL_BTS_OFF_OS | X86_DEBUGCTL_BTS_OFF_USR);
+
+	update_debugctlmsr(debugctlmsr);
+}
+
+static void intel_pmu_drain_bts_buffer(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct debug_store *ds = cpuc->ds;
+	struct bts_record {
+		u64	from;
+		u64	to;
+		u64	flags;
+	};
+	struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS];
+	struct bts_record *at, *top;
+	struct perf_output_handle handle;
+	struct perf_event_header header;
+	struct perf_sample_data data;
+	struct pt_regs regs;
+
+	if (!event)
+		return;
+
+	if (!ds)
+		return;
+
+	at  = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
+	top = (struct bts_record *)(unsigned long)ds->bts_index;
+
+	if (top <= at)
+		return;
+
+	ds->bts_index = ds->bts_buffer_base;
+
+	perf_sample_data_init(&data, 0);
+	data.period = event->hw.last_period;
+	regs.ip     = 0;
+
+	/*
+	 * Prepare a generic sample, i.e. fill in the invariant fields.
+	 * We will overwrite the from and to address before we output
+	 * the sample.
+	 */
+	perf_prepare_sample(&header, &data, event, &regs);
+
+	if (perf_output_begin(&handle, event, header.size * (top - at), 1, 1))
+		return;
+
+	for (; at < top; at++) {
+		data.ip		= at->from;
+		data.addr	= at->to;
+
+		perf_output_sample(&handle, &header, &data, event);
+	}
+
+	perf_output_end(&handle);
+
+	/* There's new data available. */
+	event->hw.interrupts++;
+	event->pending_kill = POLL_IN;
+}
+
+/*
+ * PEBS
+ */
+
+static struct event_constraint intel_core_pebs_events[] = {
+	PEBS_EVENT_CONSTRAINT(0x00c0, 0x1), /* INSTR_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0xfec1, 0x1), /* X87_OPS_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */
+	PEBS_EVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x01cb, 0x1), /* MEM_LOAD_RETIRED.L1D_MISS */
+	PEBS_EVENT_CONSTRAINT(0x02cb, 0x1), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x04cb, 0x1), /* MEM_LOAD_RETIRED.L2_MISS */
+	PEBS_EVENT_CONSTRAINT(0x08cb, 0x1), /* MEM_LOAD_RETIRED.L2_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x10cb, 0x1), /* MEM_LOAD_RETIRED.DTLB_MISS */
+	EVENT_CONSTRAINT_END
+};
+
+static struct event_constraint intel_nehalem_pebs_events[] = {
+	PEBS_EVENT_CONSTRAINT(0x00c0, 0xf), /* INSTR_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0xfec1, 0xf), /* X87_OPS_RETIRED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x00c5, 0xf), /* BR_INST_RETIRED.MISPRED */
+	PEBS_EVENT_CONSTRAINT(0x1fc7, 0xf), /* SIMD_INST_RETURED.ANY */
+	PEBS_EVENT_CONSTRAINT(0x01cb, 0xf), /* MEM_LOAD_RETIRED.L1D_MISS */
+	PEBS_EVENT_CONSTRAINT(0x02cb, 0xf), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x04cb, 0xf), /* MEM_LOAD_RETIRED.L2_MISS */
+	PEBS_EVENT_CONSTRAINT(0x08cb, 0xf), /* MEM_LOAD_RETIRED.L2_LINE_MISS */
+	PEBS_EVENT_CONSTRAINT(0x10cb, 0xf), /* MEM_LOAD_RETIRED.DTLB_MISS */
+	EVENT_CONSTRAINT_END
+};
+
+static struct event_constraint *
+intel_pebs_constraints(struct perf_event *event)
+{
+	struct event_constraint *c;
+
+	if (!event->attr.precise)
+		return NULL;
+
+	if (x86_pmu.pebs_constraints) {
+		for_each_event_constraint(c, x86_pmu.pebs_constraints) {
+			if ((event->hw.config & c->cmask) == c->code)
+				return c;
+		}
+	}
+
+	return &emptyconstraint;
+}
+
+static void intel_pmu_pebs_enable(struct hw_perf_event *hwc)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	u64 val = cpuc->pebs_enabled;
+
+	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
+
+	val |= 1ULL << hwc->idx;
+	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
+}
+
+static void intel_pmu_pebs_disable(struct hw_perf_event *hwc)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	u64 val = cpuc->pebs_enabled;
+
+	val &= ~(1ULL << hwc->idx);
+	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
+
+	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
+}
+
+static void intel_pmu_pebs_enable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->pebs_enabled)
+		wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
+}
+
+static void intel_pmu_pebs_disable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->pebs_enabled)
+		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
+}
+
+static int intel_pmu_save_and_restart(struct perf_event *event);
+static void intel_pmu_disable_event(struct perf_event *event);
+
+static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct debug_store *ds = cpuc->ds;
+	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
+	struct pebs_record_core *at, *top;
+	struct perf_sample_data data;
+	struct pt_regs regs;
+	int n;
+
+	if (!event || !ds || !x86_pmu.pebs)
+		return;
+
+	intel_pmu_pebs_disable_all();
+
+	at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
+	top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
+
+	if (top <= at)
+		goto out;
+
+	ds->pebs_index = ds->pebs_buffer_base;
+
+	if (!intel_pmu_save_and_restart(event))
+		goto out;
+
+	perf_sample_data_init(&data, 0);
+	data.period = event->hw.last_period;
+
+	n = top - at;
+
+	/*
+	 * Should not happen, we program the threshold at 1 and do not
+	 * set a reset value.
+	 */
+	WARN_ON_ONCE(n > 1);
+
+	/*
+	 * We use the interrupt regs as a base because the PEBS record
+	 * does not contain a full regs set, specifically it seems to
+	 * lack segment descriptors, which get used by things like
+	 * user_mode().
+	 *
+	 * In the simple case fix up only the IP and BP,SP regs, for
+	 * PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly.
+	 * A possible PERF_SAMPLE_REGS will have to transfer all regs.
+	 */
+	regs = *iregs;
+	regs.ip = at->ip;
+	regs.bp = at->bp;
+	regs.sp = at->sp;
+
+	if (perf_event_overflow(event, 1, &data, &regs))
+		intel_pmu_disable_event(event);
+
+out:
+	intel_pmu_pebs_enable_all();
+}
+
+static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct debug_store *ds = cpuc->ds;
+	struct pebs_record_nhm *at, *top;
+	struct perf_sample_data data;
+	struct perf_event *event = NULL;
+	struct pt_regs regs;
+	int bit, n;
+
+	if (!ds || !x86_pmu.pebs)
+		return;
+
+	intel_pmu_pebs_disable_all();
+
+	at  = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
+	top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
+
+	if (top <= at)
+		goto out;
+
+	ds->pebs_index = ds->pebs_buffer_base;
+
+	n = top - at;
+
+	/*
+	 * Should not happen, we program the threshold at 1 and do not
+	 * set a reset value.
+	 */
+	WARN_ON_ONCE(n > MAX_PEBS_EVENTS);
+
+	for ( ; at < top; at++) {
+		for_each_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) {
+			if (!cpuc->events[bit]->attr.precise)
+				continue;
+
+			event = cpuc->events[bit];
+		}
+
+		if (!event)
+			continue;
+
+		if (!intel_pmu_save_and_restart(event))
+			continue;
+
+		perf_sample_data_init(&data, 0);
+		data.period = event->hw.last_period;
+
+		/*
+		 * See the comment in intel_pmu_drain_pebs_core()
+		 */
+		regs = *iregs;
+		regs.ip = at->ip;
+		regs.bp = at->bp;
+		regs.sp = at->sp;
+
+		if (perf_event_overflow(event, 1, &data, &regs))
+			intel_pmu_disable_event(event);
+	}
+out:
+	intel_pmu_pebs_enable_all();
+}
+
+/*
+ * BTS, PEBS probe and setup
+ */
+
+static void intel_ds_init(void)
+{
+	/*
+	 * No support for 32bit formats
+	 */
+	if (!boot_cpu_has(X86_FEATURE_DTES64))
+		return;
+
+	x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
+	x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
+	if (x86_pmu.pebs) {
+		int format = 0;
+
+		if (x86_pmu.version > 1) {
+			u64 capabilities;
+			/*
+			 * v2+ has a PEBS format field
+			 */
+			rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
+			format = (capabilities >> 8) & 0xf;
+		}
+
+		switch (format) {
+		case 0:
+			printk(KERN_CONT "PEBS v0, ");
+			x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
+			x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
+			x86_pmu.pebs_constraints = intel_core_pebs_events;
+			break;
+
+		case 1:
+			printk(KERN_CONT "PEBS v1, ");
+			x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
+			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
+			x86_pmu.pebs_constraints = intel_nehalem_pebs_events;
+			break;
+
+		default:
+			printk(KERN_CONT "PEBS unknown format: %d, ", format);
+			x86_pmu.pebs = 0;
+			break;
+		}
+	}
+}
+
+#else /* CONFIG_CPU_SUP_INTEL */
+
+static int reseve_ds_buffers(void)
+{
+	return 0;
+}
+
+static void release_ds_buffers(void)
+{
+}
+
+#endif /* CONFIG_CPU_SUP_INTEL */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 80acbf3..42307b5 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -203,8 +203,9 @@ struct perf_event_attr {
 				enable_on_exec :  1, /* next exec enables     */
 				task           :  1, /* trace fork/exit       */
 				watermark      :  1, /* wakeup_watermark      */
+				precise        :  1, /* OoO invariant counter */
 
-				__reserved_1   : 49;
+				__reserved_1   : 48;
 
 	union {
 		__u32		wakeup_events;	  /* wakeup every n events */

[PATCH 07/14] perf: Add attr->precise support to raw event parsing

[Peter Zijlstra]

[-- Attachment #1: perf-tools-precise.patch --]
[-- Type: text/plain, Size: 816 bytes --]

Minimal userspace interface to the new 'precise' events flag.

Can be used like: perf top -e r00c0p
Which will use PEBS to sample retired instructions

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 tools/perf/util/parse-events.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-2.6/tools/perf/util/parse-events.c
===================================================================
--- linux-2.6.orig/tools/perf/util/parse-events.c
+++ linux-2.6/tools/perf/util/parse-events.c
@@ -656,6 +656,10 @@ parse_raw_event(const char **strp, struc
 		return EVT_FAILED;
 	n = hex2u64(str + 1, &config);
 	if (n > 0) {
+		if (str[n+1] == 'p') {
+			attr->precise = 1;
+			n++;
+		}
 		*strp = str + n + 1;
 		attr->type = PERF_TYPE_RAW;
 		attr->config = config;

-- 

[tip:perf/pebs] perf: Add attr->precise support to raw event parsing

[tip-bot for Peter Zijlstra]

Commit-ID:  69fef0d2e2c2c049ef4207a52e78b50d527bd85a
Gitweb:     http://git.kernel.org/tip/69fef0d2e2c2c049ef4207a52e78b50d527bd85a
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 4 Mar 2010 13:57:24 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:32 +0100

perf: Add attr->precise support to raw event parsing

Minimal userspace interface to the new 'precise' events flag.

Can be used like "perf top -e r00c0p" which will use PEBS to sample
retired instructions.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.468665803@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 tools/perf/util/parse-events.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 05d0c5c..a201445 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -656,6 +656,10 @@ parse_raw_event(const char **strp, struct perf_event_attr *attr)
 		return EVT_FAILED;
 	n = hex2u64(str + 1, &config);
 	if (n > 0) {
+		if (str[n+1] == 'p') {
+			attr->precise = 1;
+			n++;
+		}
 		*strp = str + n + 1;
 		attr->type = PERF_TYPE_RAW;
 		attr->config = config;

[PATCH 08/14] perf, x86: Implement simple LBR support

[Peter Zijlstra]

[-- Attachment #1: perf-lbr.patch --]
[-- Type: text/plain, Size: 9545 bytes --]

Implement support for Intel LBR stacks that support
FREEZE_LBRS_ON_PMI. We do not (yet?) support the LBR config register
because that is SMT wide and would also put undue restraints on the
PEBS users.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c           |   18 ++
 arch/x86/kernel/cpu/perf_event_intel.c     |   13 +
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |  228 +++++++++++++++++++++++++++++
 include/linux/perf_event.h                 |   11 +
 4 files changed, 270 insertions(+)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -48,6 +48,8 @@ struct amd_nb {
 	struct event_constraint event_constraints[X86_PMC_IDX_MAX];
 };
 
+#define MAX_LBR_ENTRIES		16
+
 struct cpu_hw_events {
 	/*
 	 * Generic x86 PMC bits
@@ -70,6 +72,14 @@ struct cpu_hw_events {
 	u64			pebs_enabled;
 
 	/*
+	 * Intel LBR bits
+	 */
+	int				lbr_users;
+	void				*lbr_context;
+	struct perf_branch_stack	lbr_stack;
+	struct perf_branch_entry	lbr_entries[MAX_LBR_ENTRIES];
+
+	/*
 	 * AMD specific bits
 	 */
 	struct amd_nb		*amd_nb;
@@ -154,6 +164,13 @@ struct x86_pmu {
 	int		pebs_record_size;
 	void		(*drain_pebs)(struct pt_regs *regs);
 	struct event_constraint *pebs_constraints;
+
+	/*
+	 * Intel LBR
+	 */
+	unsigned long	lbr_tos, lbr_from, lbr_to; /* MSR base regs       */
+	int		lbr_nr;			   /* hardware stack size */
+	int		lbr_format;		   /* hardware format     */
 };
 
 static struct x86_pmu x86_pmu __read_mostly;
@@ -1238,6 +1255,7 @@ undo:
 
 #include "perf_event_amd.c"
 #include "perf_event_p6.c"
+#include "perf_event_intel_lbr.c"
 #include "perf_event_intel_ds.c"
 #include "perf_event_intel.c"
 
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -480,6 +480,7 @@ static void intel_pmu_disable_all(void)
 		intel_pmu_disable_bts();
 
 	intel_pmu_pebs_disable_all();
+	intel_pmu_lbr_disable_all();
 }
 
 static void intel_pmu_enable_all(void)
@@ -499,6 +500,7 @@ static void intel_pmu_enable_all(void)
 	}
 
 	intel_pmu_pebs_enable_all();
+	intel_pmu_lbr_enable_all();
 }
 
 static inline u64 intel_pmu_get_status(void)
@@ -675,6 +677,8 @@ again:
 	inc_irq_stat(apic_perf_irqs);
 	ack = status;
 
+	intel_pmu_lbr_read();
+
 	/*
 	 * PEBS overflow sets bit 62 in the global status register
 	 */
@@ -847,6 +851,8 @@ static __init int intel_pmu_init(void)
 		memcpy(hw_cache_event_ids, core2_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_core();
+
 		x86_pmu.event_constraints = intel_core2_event_constraints;
 		pr_cont("Core2 events, ");
 		break;
@@ -856,13 +862,18 @@ static __init int intel_pmu_init(void)
 		memcpy(hw_cache_event_ids, nehalem_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_nhm();
+
 		x86_pmu.event_constraints = intel_nehalem_event_constraints;
 		pr_cont("Nehalem/Corei7 events, ");
 		break;
+
 	case 28: /* Atom */
 		memcpy(hw_cache_event_ids, atom_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_atom();
+
 		x86_pmu.event_constraints = intel_gen_event_constraints;
 		pr_cont("Atom events, ");
 		break;
@@ -872,6 +883,8 @@ static __init int intel_pmu_init(void)
 		memcpy(hw_cache_event_ids, westmere_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_nhm();
+
 		x86_pmu.event_constraints = intel_westmere_event_constraints;
 		pr_cont("Westmere events, ");
 		break;
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_lbr.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -0,0 +1,228 @@
+#ifdef CONFIG_CPU_SUP_INTEL
+
+enum {
+	LBR_FORMAT_32		= 0x00,
+	LBR_FORMAT_LIP		= 0x01,
+	LBR_FORMAT_EIP		= 0x02,
+	LBR_FORMAT_EIP_FLAGS	= 0x03,
+};
+
+/*
+ * We only support LBR implementations that have FREEZE_LBRS_ON_PMI
+ * otherwise it becomes near impossible to get a reliable stack.
+ */
+
+#define X86_DEBUGCTL_LBR               		(1 << 0)
+#define X86_DEBUGCTL_FREEZE_LBRS_ON_PMI		(1 << 11)
+
+static void __intel_pmu_lbr_enable(void)
+{
+	u64 debugctl;
+
+	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+	debugctl |= (X86_DEBUGCTL_LBR | X86_DEBUGCTL_FREEZE_LBRS_ON_PMI);
+	wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+}
+
+static void __intel_pmu_lbr_disable(void)
+{
+	u64 debugctl;
+
+	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+	debugctl &= ~(X86_DEBUGCTL_LBR | X86_DEBUGCTL_FREEZE_LBRS_ON_PMI);
+	wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+}
+
+static void intel_pmu_lbr_reset_32(void)
+{
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++)
+		wrmsrl(x86_pmu.lbr_from + i, 0);
+}
+
+static void intel_pmu_lbr_reset_64(void)
+{
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++) {
+		wrmsrl(x86_pmu.lbr_from + i, 0);
+		wrmsrl(x86_pmu.lbr_to   + i, 0);
+	}
+}
+
+static void intel_pmu_lbr_reset(void)
+{
+	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+		intel_pmu_lbr_reset_32();
+	else
+		intel_pmu_lbr_reset_64();
+}
+
+static void intel_pmu_lbr_enable(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (!x86_pmu.lbr_nr)
+		return;
+
+	WARN_ON(cpuc->enabled);
+
+	/*
+	 * Reset the LBR stack if this is the first LBR user or
+	 * we changed task context so as to avoid data leaks.
+	 */
+
+	if (!cpuc->lbr_users ||
+	    (event->ctx->task && cpuc->lbr_context != event->ctx)) {
+		intel_pmu_lbr_reset();
+		cpuc->lbr_context = event->ctx;
+	}
+
+	cpuc->lbr_users++;
+}
+
+static void intel_pmu_lbr_disable(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (!x86_pmu.lbr_nr)
+		return;
+
+	cpuc->lbr_users--;
+
+	BUG_ON(cpuc->lbr_users < 0);
+	WARN_ON(cpuc->enabled);
+}
+
+static void intel_pmu_lbr_enable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->lbr_users)
+		__intel_pmu_lbr_enable();
+}
+
+static void intel_pmu_lbr_disable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->lbr_users)
+		__intel_pmu_lbr_disable();
+}
+
+static inline u64 intel_pmu_lbr_tos(void)
+{
+	u64 tos;
+
+	rdmsrl(x86_pmu.lbr_tos, tos);
+
+	return tos;
+}
+
+static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
+{
+	unsigned long mask = x86_pmu.lbr_nr - 1;
+	u64 tos = intel_pmu_lbr_tos();
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++, tos--) {
+		unsigned long lbr_idx = (tos - i) & mask;
+		union {
+			struct {
+				u32 from;
+				u32 to;
+			};
+			u64     lbr;
+		} msr_lastbranch;
+
+		rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr);
+
+		cpuc->lbr_entries[i].from  = msr_lastbranch.from;
+		cpuc->lbr_entries[i].to    = msr_lastbranch.to;
+		cpuc->lbr_entries[i].flags = 0;
+	}
+	cpuc->lbr_stack.nr = i;
+}
+
+#define LBR_FROM_FLAG_MISPRED  (1ULL << 63)
+
+/*
+ * Due to lack of segmentation in Linux the effective address (offset)
+ * is the same as the linear address, allowing us to merge the LIP and EIP
+ * LBR formats.
+ */
+static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
+{
+	unsigned long mask = x86_pmu.lbr_nr - 1;
+	u64 tos = intel_pmu_lbr_tos();
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++, tos--) {
+		unsigned long lbr_idx = (tos - i) & mask;
+		u64 from, to, flags = 0;
+
+		rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
+		rdmsrl(x86_pmu.lbr_to   + lbr_idx, to);
+
+		if (x86_pmu.lbr_format == LBR_FORMAT_EIP_FLAGS) {
+			flags = !!(from & LBR_FROM_FLAG_MISPRED);
+			from = (u64)((((s64)from) << 1) >> 1);
+		}
+
+		cpuc->lbr_entries[i].from  = from;
+		cpuc->lbr_entries[i].to    = to;
+		cpuc->lbr_entries[i].flags = flags;
+	}
+	cpuc->lbr_stack.nr = i;
+}
+
+static void intel_pmu_lbr_read(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (!cpuc->lbr_users)
+		return;
+
+	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+		intel_pmu_lbr_read_32(cpuc);
+	else
+		intel_pmu_lbr_read_64(cpuc);
+}
+
+static int intel_pmu_lbr_format(void)
+{
+	u64 capabilities;
+
+	rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
+	return capabilities & 0x1f;
+}
+
+static void intel_pmu_lbr_init_core(void)
+{
+	x86_pmu.lbr_format = intel_pmu_lbr_format();
+	x86_pmu.lbr_nr     = 4;
+	x86_pmu.lbr_tos    = 0x01c9;
+	x86_pmu.lbr_from   = 0x40;
+	x86_pmu.lbr_to     = 0x60;
+}
+
+static void intel_pmu_lbr_init_nhm(void)
+{
+	x86_pmu.lbr_format = intel_pmu_lbr_format();
+	x86_pmu.lbr_nr     = 16;
+	x86_pmu.lbr_tos    = 0x01c9;
+	x86_pmu.lbr_from   = 0x680;
+	x86_pmu.lbr_to     = 0x6c0;
+}
+
+static void intel_pmu_lbr_init_atom(void)
+{
+	x86_pmu.lbr_format = intel_pmu_lbr_format();
+	x86_pmu.lbr_nr	   = 8;
+	x86_pmu.lbr_tos    = 0x01c9;
+	x86_pmu.lbr_from   = 0x40;
+	x86_pmu.lbr_to     = 0x60;
+}
+
+#endif /* CONFIG_CPU_SUP_INTEL */
Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -467,6 +467,17 @@ struct perf_raw_record {
 	void				*data;
 };
 
+struct perf_branch_entry {
+	__u64				from;
+	__u64				to;
+	__u64				flags;
+};
+
+struct perf_branch_stack {
+	__u64				nr;
+	struct perf_branch_entry	entries[0];
+};
+
 struct task_struct;
 
 /**

-- 

[tip:perf/pebs] perf, x86: Implement simple LBR support

[tip-bot for Peter Zijlstra]

Commit-ID:  caff2befffe899e63df5cc760b7ed01cfd902685
Gitweb:     http://git.kernel.org/tip/caff2befffe899e63df5cc760b7ed01cfd902685
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 3 Mar 2010 12:02:30 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:32 +0100

perf, x86: Implement simple LBR support

Implement simple suport Intel Last-Branch-Record, it supports all
hardware that implements FREEZE_LBRS_ON_PMI, but does not (yet) implement
the LBR config register.

The Intel LBR is a FIFO of From,To addresses describing the last few
branches the hardware took.

This patch does not add perf interface to the LBR, but merely provides an
interface for internal use.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.544191154@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c           |   18 +++
 arch/x86/kernel/cpu/perf_event_intel.c     |   13 ++
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |  228 ++++++++++++++++++++++++++++
 include/linux/perf_event.h                 |   11 ++
 4 files changed, 270 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 0c03d5c..1badff6 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -48,6 +48,8 @@ struct amd_nb {
 	struct event_constraint event_constraints[X86_PMC_IDX_MAX];
 };
 
+#define MAX_LBR_ENTRIES		16
+
 struct cpu_hw_events {
 	/*
 	 * Generic x86 PMC bits
@@ -70,6 +72,14 @@ struct cpu_hw_events {
 	u64			pebs_enabled;
 
 	/*
+	 * Intel LBR bits
+	 */
+	int				lbr_users;
+	void				*lbr_context;
+	struct perf_branch_stack	lbr_stack;
+	struct perf_branch_entry	lbr_entries[MAX_LBR_ENTRIES];
+
+	/*
 	 * AMD specific bits
 	 */
 	struct amd_nb		*amd_nb;
@@ -159,6 +169,13 @@ struct x86_pmu {
 	int		pebs_record_size;
 	void		(*drain_pebs)(struct pt_regs *regs);
 	struct event_constraint *pebs_constraints;
+
+	/*
+	 * Intel LBR
+	 */
+	unsigned long	lbr_tos, lbr_from, lbr_to; /* MSR base regs       */
+	int		lbr_nr;			   /* hardware stack size */
+	int		lbr_format;		   /* hardware format     */
 };
 
 static struct x86_pmu x86_pmu __read_mostly;
@@ -1237,6 +1254,7 @@ undo:
 
 #include "perf_event_amd.c"
 #include "perf_event_p6.c"
+#include "perf_event_intel_lbr.c"
 #include "perf_event_intel_ds.c"
 #include "perf_event_intel.c"
 
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 1144641..44f6ed4 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -480,6 +480,7 @@ static void intel_pmu_disable_all(void)
 		intel_pmu_disable_bts();
 
 	intel_pmu_pebs_disable_all();
+	intel_pmu_lbr_disable_all();
 }
 
 static void intel_pmu_enable_all(void)
@@ -499,6 +500,7 @@ static void intel_pmu_enable_all(void)
 	}
 
 	intel_pmu_pebs_enable_all();
+	intel_pmu_lbr_enable_all();
 }
 
 static inline u64 intel_pmu_get_status(void)
@@ -674,6 +676,8 @@ again:
 	inc_irq_stat(apic_perf_irqs);
 	ack = status;
 
+	intel_pmu_lbr_read();
+
 	/*
 	 * PEBS overflow sets bit 62 in the global status register
 	 */
@@ -848,6 +852,8 @@ static __init int intel_pmu_init(void)
 		memcpy(hw_cache_event_ids, core2_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_core();
+
 		x86_pmu.event_constraints = intel_core2_event_constraints;
 		pr_cont("Core2 events, ");
 		break;
@@ -857,13 +863,18 @@ static __init int intel_pmu_init(void)
 		memcpy(hw_cache_event_ids, nehalem_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_nhm();
+
 		x86_pmu.event_constraints = intel_nehalem_event_constraints;
 		pr_cont("Nehalem/Corei7 events, ");
 		break;
+
 	case 28: /* Atom */
 		memcpy(hw_cache_event_ids, atom_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_atom();
+
 		x86_pmu.event_constraints = intel_gen_event_constraints;
 		pr_cont("Atom events, ");
 		break;
@@ -873,6 +884,8 @@ static __init int intel_pmu_init(void)
 		memcpy(hw_cache_event_ids, westmere_hw_cache_event_ids,
 		       sizeof(hw_cache_event_ids));
 
+		intel_pmu_lbr_init_nhm();
+
 		x86_pmu.event_constraints = intel_westmere_event_constraints;
 		pr_cont("Westmere events, ");
 		break;
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
new file mode 100644
index 0000000..ea3e99e
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -0,0 +1,228 @@
+#ifdef CONFIG_CPU_SUP_INTEL
+
+enum {
+	LBR_FORMAT_32		= 0x00,
+	LBR_FORMAT_LIP		= 0x01,
+	LBR_FORMAT_EIP		= 0x02,
+	LBR_FORMAT_EIP_FLAGS	= 0x03,
+};
+
+/*
+ * We only support LBR implementations that have FREEZE_LBRS_ON_PMI
+ * otherwise it becomes near impossible to get a reliable stack.
+ */
+
+#define X86_DEBUGCTL_LBR               		(1 << 0)
+#define X86_DEBUGCTL_FREEZE_LBRS_ON_PMI		(1 << 11)
+
+static void __intel_pmu_lbr_enable(void)
+{
+	u64 debugctl;
+
+	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+	debugctl |= (X86_DEBUGCTL_LBR | X86_DEBUGCTL_FREEZE_LBRS_ON_PMI);
+	wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+}
+
+static void __intel_pmu_lbr_disable(void)
+{
+	u64 debugctl;
+
+	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+	debugctl &= ~(X86_DEBUGCTL_LBR | X86_DEBUGCTL_FREEZE_LBRS_ON_PMI);
+	wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+}
+
+static void intel_pmu_lbr_reset_32(void)
+{
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++)
+		wrmsrl(x86_pmu.lbr_from + i, 0);
+}
+
+static void intel_pmu_lbr_reset_64(void)
+{
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++) {
+		wrmsrl(x86_pmu.lbr_from + i, 0);
+		wrmsrl(x86_pmu.lbr_to   + i, 0);
+	}
+}
+
+static void intel_pmu_lbr_reset(void)
+{
+	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+		intel_pmu_lbr_reset_32();
+	else
+		intel_pmu_lbr_reset_64();
+}
+
+static void intel_pmu_lbr_enable(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (!x86_pmu.lbr_nr)
+		return;
+
+	WARN_ON(cpuc->enabled);
+
+	/*
+	 * Reset the LBR stack if this is the first LBR user or
+	 * we changed task context so as to avoid data leaks.
+	 */
+
+	if (!cpuc->lbr_users ||
+	    (event->ctx->task && cpuc->lbr_context != event->ctx)) {
+		intel_pmu_lbr_reset();
+		cpuc->lbr_context = event->ctx;
+	}
+
+	cpuc->lbr_users++;
+}
+
+static void intel_pmu_lbr_disable(struct perf_event *event)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (!x86_pmu.lbr_nr)
+		return;
+
+	cpuc->lbr_users--;
+
+	BUG_ON(cpuc->lbr_users < 0);
+	WARN_ON(cpuc->enabled);
+}
+
+static void intel_pmu_lbr_enable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->lbr_users)
+		__intel_pmu_lbr_enable();
+}
+
+static void intel_pmu_lbr_disable_all(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (cpuc->lbr_users)
+		__intel_pmu_lbr_disable();
+}
+
+static inline u64 intel_pmu_lbr_tos(void)
+{
+	u64 tos;
+
+	rdmsrl(x86_pmu.lbr_tos, tos);
+
+	return tos;
+}
+
+static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
+{
+	unsigned long mask = x86_pmu.lbr_nr - 1;
+	u64 tos = intel_pmu_lbr_tos();
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++, tos--) {
+		unsigned long lbr_idx = (tos - i) & mask;
+		union {
+			struct {
+				u32 from;
+				u32 to;
+			};
+			u64     lbr;
+		} msr_lastbranch;
+
+		rdmsrl(x86_pmu.lbr_from + lbr_idx, msr_lastbranch.lbr);
+
+		cpuc->lbr_entries[i].from  = msr_lastbranch.from;
+		cpuc->lbr_entries[i].to    = msr_lastbranch.to;
+		cpuc->lbr_entries[i].flags = 0;
+	}
+	cpuc->lbr_stack.nr = i;
+}
+
+#define LBR_FROM_FLAG_MISPRED  (1ULL << 63)
+
+/*
+ * Due to lack of segmentation in Linux the effective address (offset)
+ * is the same as the linear address, allowing us to merge the LIP and EIP
+ * LBR formats.
+ */
+static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
+{
+	unsigned long mask = x86_pmu.lbr_nr - 1;
+	u64 tos = intel_pmu_lbr_tos();
+	int i;
+
+	for (i = 0; i < x86_pmu.lbr_nr; i++, tos--) {
+		unsigned long lbr_idx = (tos - i) & mask;
+		u64 from, to, flags = 0;
+
+		rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
+		rdmsrl(x86_pmu.lbr_to   + lbr_idx, to);
+
+		if (x86_pmu.lbr_format == LBR_FORMAT_EIP_FLAGS) {
+			flags = !!(from & LBR_FROM_FLAG_MISPRED);
+			from = (u64)((((s64)from) << 1) >> 1);
+		}
+
+		cpuc->lbr_entries[i].from  = from;
+		cpuc->lbr_entries[i].to    = to;
+		cpuc->lbr_entries[i].flags = flags;
+	}
+	cpuc->lbr_stack.nr = i;
+}
+
+static void intel_pmu_lbr_read(void)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+	if (!cpuc->lbr_users)
+		return;
+
+	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+		intel_pmu_lbr_read_32(cpuc);
+	else
+		intel_pmu_lbr_read_64(cpuc);
+}
+
+static int intel_pmu_lbr_format(void)
+{
+	u64 capabilities;
+
+	rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
+	return capabilities & 0x1f;
+}
+
+static void intel_pmu_lbr_init_core(void)
+{
+	x86_pmu.lbr_format = intel_pmu_lbr_format();
+	x86_pmu.lbr_nr     = 4;
+	x86_pmu.lbr_tos    = 0x01c9;
+	x86_pmu.lbr_from   = 0x40;
+	x86_pmu.lbr_to     = 0x60;
+}
+
+static void intel_pmu_lbr_init_nhm(void)
+{
+	x86_pmu.lbr_format = intel_pmu_lbr_format();
+	x86_pmu.lbr_nr     = 16;
+	x86_pmu.lbr_tos    = 0x01c9;
+	x86_pmu.lbr_from   = 0x680;
+	x86_pmu.lbr_to     = 0x6c0;
+}
+
+static void intel_pmu_lbr_init_atom(void)
+{
+	x86_pmu.lbr_format = intel_pmu_lbr_format();
+	x86_pmu.lbr_nr	   = 8;
+	x86_pmu.lbr_tos    = 0x01c9;
+	x86_pmu.lbr_from   = 0x40;
+	x86_pmu.lbr_to     = 0x60;
+}
+
+#endif /* CONFIG_CPU_SUP_INTEL */
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 42307b5..ab4fd9e 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -467,6 +467,17 @@ struct perf_raw_record {
 	void				*data;
 };
 
+struct perf_branch_entry {
+	__u64				from;
+	__u64				to;
+	__u64				flags;
+};
+
+struct perf_branch_stack {
+	__u64				nr;
+	struct perf_branch_entry	entries[0];
+};
+
 struct task_struct;
 
 /**

[PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

[Peter Zijlstra]

[-- Attachment #1: perf-pebs-lbr.patch --]
[-- Type: text/plain, Size: 8310 bytes --]

PEBS always reports the IP+1, that is the instruction after the one
that got sampled, cure this by using the LBR to reliably rewind the
instruction stream.

CC: Masami Hiramatsu <mhiramat@redhat.com>
CC: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/include/asm/perf_event.h         |   19 ++++++
 arch/x86/kernel/cpu/perf_event.c          |   70 ++++++++++++-------------
 arch/x86/kernel/cpu/perf_event_intel.c    |    4 -
 arch/x86/kernel/cpu/perf_event_intel_ds.c |   84 +++++++++++++++++++++++++++++-
 include/linux/perf_event.h                |    6 ++
 5 files changed, 144 insertions(+), 39 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -29,6 +29,41 @@
 #include <asm/stacktrace.h>
 #include <asm/nmi.h>
 
+/*
+ * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
+ */
+static unsigned long
+copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
+{
+	unsigned long offset, addr = (unsigned long)from;
+	int type = in_nmi() ? KM_NMI : KM_IRQ0;
+	unsigned long size, len = 0;
+	struct page *page;
+	void *map;
+	int ret;
+
+	do {
+		ret = __get_user_pages_fast(addr, 1, 0, &page);
+		if (!ret)
+			break;
+
+		offset = addr & (PAGE_SIZE - 1);
+		size = min(PAGE_SIZE - offset, n - len);
+
+		map = kmap_atomic(page, type);
+		memcpy(to, map+offset, size);
+		kunmap_atomic(map, type);
+		put_page(page);
+
+		len  += size;
+		to   += size;
+		addr += size;
+
+	} while (len < n);
+
+	return len;
+}
+
 static u64 perf_event_mask __read_mostly;
 
 struct event_constraint {
@@ -1516,41 +1551,6 @@ perf_callchain_kernel(struct pt_regs *re
 	dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry);
 }
 
-/*
- * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
- */
-static unsigned long
-copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
-{
-	unsigned long offset, addr = (unsigned long)from;
-	int type = in_nmi() ? KM_NMI : KM_IRQ0;
-	unsigned long size, len = 0;
-	struct page *page;
-	void *map;
-	int ret;
-
-	do {
-		ret = __get_user_pages_fast(addr, 1, 0, &page);
-		if (!ret)
-			break;
-
-		offset = addr & (PAGE_SIZE - 1);
-		size = min(PAGE_SIZE - offset, n - len);
-
-		map = kmap_atomic(page, type);
-		memcpy(to, map+offset, size);
-		kunmap_atomic(map, type);
-		put_page(page);
-
-		len  += size;
-		to   += size;
-		addr += size;
-
-	} while (len < n);
-
-	return len;
-}
-
 static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
 {
 	unsigned long bytes;
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -547,7 +547,7 @@ static void intel_pmu_disable_event(stru
 	x86_pmu_disable_event(event);
 
 	if (unlikely(event->attr.precise))
-		intel_pmu_pebs_disable(hwc);
+		intel_pmu_pebs_disable(event);
 }
 
 static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
@@ -600,7 +600,7 @@ static void intel_pmu_enable_event(struc
 	}
 
 	if (unlikely(event->attr.precise))
-		intel_pmu_pebs_enable(hwc);
+		intel_pmu_pebs_enable(event);
 
 	__x86_pmu_enable_event(hwc);
 }
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -331,26 +331,32 @@ intel_pebs_constraints(struct perf_event
 	return &emptyconstraint;
 }
 
-static void intel_pmu_pebs_enable(struct hw_perf_event *hwc)
+static void intel_pmu_pebs_enable(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val = cpuc->pebs_enabled;
 
 	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
 
 	val |= 1ULL << hwc->idx;
 	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
+
+	intel_pmu_lbr_enable(event);
 }
 
-static void intel_pmu_pebs_disable(struct hw_perf_event *hwc)
+static void intel_pmu_pebs_disable(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val = cpuc->pebs_enabled;
 
 	val &= ~(1ULL << hwc->idx);
 	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
 
 	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
+
+	intel_pmu_lbr_disable(event);
 }
 
 static void intel_pmu_pebs_enable_all(void)
@@ -369,6 +375,70 @@ static void intel_pmu_pebs_disable_all(v
 		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
 }
 
+#include <asm/insn.h>
+
+#define MAX_INSN_SIZE	16
+
+static inline bool kernel_ip(unsigned long ip)
+{
+#ifdef CONFIG_X86_32
+	return ip > PAGE_OFFSET;
+#else
+	return (long)ip < 0;
+#endif
+}
+
+static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	unsigned long from = cpuc->lbr_entries[0].from;
+	unsigned long old_to, to = cpuc->lbr_entries[0].to;
+	unsigned long ip = regs->ip;
+
+	if (!cpuc->lbr_stack.nr || !from || !to)
+		return 0;
+
+	if (ip < to)
+		return 0;
+
+	/*
+	 * We sampled a branch insn, rewind using the LBR stack
+	 */
+	if (ip == to) {
+		regs->ip = from;
+		return 1;
+	}
+
+	do {
+		struct insn insn;
+		u8 buf[MAX_INSN_SIZE];
+		void *kaddr;
+
+		old_to = to;
+		if (!kernel_ip(ip)) {
+			int bytes, size = min_t(int, MAX_INSN_SIZE, ip - to);
+
+			bytes = copy_from_user_nmi(buf, (void __user *)to, size);
+			if (bytes != size)
+				return 0;
+
+			kaddr = buf;
+		} else
+			kaddr = (void *)to;
+
+		kernel_insn_init(&insn, kaddr);
+		insn_get_length(&insn);
+		to += insn.length;
+	} while (to < ip);
+
+	if (to == ip) {
+		regs->ip = old_to;
+		return 1;
+	}
+
+	return 0;
+}
+
 static int intel_pmu_save_and_restart(struct perf_event *event);
 static void intel_pmu_disable_event(struct perf_event *event);
 
@@ -427,6 +497,11 @@ static void intel_pmu_drain_pebs_core(st
 	regs.bp = at->bp;
 	regs.sp = at->sp;
 
+	if (intel_pmu_pebs_fixup_ip(&regs))
+		regs.flags |= PERF_EFLAGS_EXACT;
+	else
+		regs.flags &= ~PERF_EFLAGS_EXACT;
+
 	if (perf_event_overflow(event, 1, &data, &regs))
 		intel_pmu_disable_event(event);
 
@@ -497,6 +572,11 @@ static void intel_pmu_drain_pebs_nhm(str
 		regs.bp = at->bp;
 		regs.sp = at->sp;
 
+		if (intel_pmu_pebs_fixup_ip(&regs))
+			regs.flags |= PERF_EFLAGS_EXACT;
+		else
+			regs.flags &= ~PERF_EFLAGS_EXACT;
+
 		if (perf_event_overflow(event, 1, &data, &regs))
 			intel_pmu_disable_event(event);
 	}
Index: linux-2.6/arch/x86/include/asm/perf_event.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/perf_event.h
+++ linux-2.6/arch/x86/include/asm/perf_event.h
@@ -136,6 +136,25 @@ extern void perf_events_lapic_init(void)
 
 #define PERF_EVENT_INDEX_OFFSET			0
 
+/*
+ * Abuse bit 3 of the cpu eflags register to indicate proper PEBS IP fixups.
+ * This flag is otherwise unused and ABI specified to be 0, so nobody should
+ * care what we do with it.
+ */
+#define PERF_EFLAGS_EXACT	(1UL << 3)
+
+#define perf_misc_flags(regs)				\
+({	int misc = 0;					\
+	if (user_mode(regs))				\
+		misc |= PERF_RECORD_MISC_USER;		\
+	else						\
+		misc |= PERF_RECORD_MISC_KERNEL;	\
+	if (regs->flags & PERF_EFLAGS_EXACT)		\
+		misc |= PERF_RECORD_MISC_EXACT;		\
+	misc; })
+
+#define perf_instruction_pointer(regs)	((regs)->ip)
+
 #else
 static inline void init_hw_perf_events(void)		{ }
 static inline void perf_events_lapic_init(void)	{ }
Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -294,6 +294,12 @@ struct perf_event_mmap_page {
 #define PERF_RECORD_MISC_USER			(2 << 0)
 #define PERF_RECORD_MISC_HYPERVISOR		(3 << 0)
 
+#define PERF_RECORD_MISC_EXACT			(1 << 14)
+/*
+ * Reserve the last bit to indicate some extended misc field
+ */
+#define PERF_RECORD_MISC_EXT_RESERVED		(1 << 15)
+
 struct perf_event_header {
 	__u32	type;
 	__u16	misc;

-- 

Re: [PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

[Masami Hiramatsu]

Peter Zijlstra wrote:
> PEBS always reports the IP+1, that is the instruction after the one
> that got sampled, cure this by using the LBR to reliably rewind the
> instruction stream.
> 
> CC: Masami Hiramatsu <mhiramat@redhat.com>
> CC: Yanmin Zhang <yanmin_zhang@linux.intel.com>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> LKML-Reference: <new-submission>
> ---
>  arch/x86/include/asm/perf_event.h         |   19 ++++++
>  arch/x86/kernel/cpu/perf_event.c          |   70 ++++++++++++-------------
>  arch/x86/kernel/cpu/perf_event_intel.c    |    4 -
>  arch/x86/kernel/cpu/perf_event_intel_ds.c |   84 +++++++++++++++++++++++++++++-
>  include/linux/perf_event.h                |    6 ++
>  5 files changed, 144 insertions(+), 39 deletions(-)
> 
[...]
> Index: linux-2.6/arch/x86/include/asm/perf_event.h
> ===================================================================
> --- linux-2.6.orig/arch/x86/include/asm/perf_event.h
> +++ linux-2.6/arch/x86/include/asm/perf_event.h
> @@ -136,6 +136,25 @@ extern void perf_events_lapic_init(void)
>  
>  #define PERF_EVENT_INDEX_OFFSET			0
>  
> +/*
> + * Abuse bit 3 of the cpu eflags register to indicate proper PEBS IP fixups.
> + * This flag is otherwise unused and ABI specified to be 0, so nobody should
> + * care what we do with it.
> + */
> +#define PERF_EFLAGS_EXACT	(1UL << 3)
 > +
> +#define perf_misc_flags(regs)				\
> +({	int misc = 0;					\
> +	if (user_mode(regs))				\
> +		misc |= PERF_RECORD_MISC_USER;		\
> +	else						\
> +		misc |= PERF_RECORD_MISC_KERNEL;	\
> +	if (regs->flags & PERF_EFLAGS_EXACT)		\
> +		misc |= PERF_RECORD_MISC_EXACT;		\
> +	misc; })
> +
> +#define perf_instruction_pointer(regs)	((regs)->ip)

Hmm, why don't you use instruction_pointer() defined in asm/ptrace.h?
And I couldn't find any user of this macro in this patch...

Others looks good to me :)

Thank you,

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

[Peter Zijlstra]

On Thu, 2010-03-04 at 11:21 -0500, Masami Hiramatsu wrote:
> Peter Zijlstra wrote:

> > +#define perf_misc_flags(regs)				\
> > +({	int misc = 0;					\
> > +	if (user_mode(regs))				\
> > +		misc |= PERF_RECORD_MISC_USER;		\
> > +	else						\
> > +		misc |= PERF_RECORD_MISC_KERNEL;	\
> > +	if (regs->flags & PERF_EFLAGS_EXACT)		\
> > +		misc |= PERF_RECORD_MISC_EXACT;		\
> > +	misc; })
> > +
> > +#define perf_instruction_pointer(regs)	((regs)->ip)
> 
> Hmm, why don't you use instruction_pointer() defined in asm/ptrace.h?
> And I couldn't find any user of this macro in this patch...

perf_instruction_pointer() is used in kernel/perf_event.c, and yeah I
could have used instruction_pointer() but that's yet another wrapper.

Anyway, Yanmin is poking at doing kvm-guest profiling and will likely
rewrite all of the perf_misc() and perf_instruction_pointer() stuff
soon.

Re: [PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

[Masami Hiramatsu]

Peter Zijlstra wrote:
> On Thu, 2010-03-04 at 11:21 -0500, Masami Hiramatsu wrote:
>> Peter Zijlstra wrote:
> 
>>> +#define perf_misc_flags(regs)				\
>>> +({	int misc = 0;					\
>>> +	if (user_mode(regs))				\
>>> +		misc |= PERF_RECORD_MISC_USER;		\
>>> +	else						\
>>> +		misc |= PERF_RECORD_MISC_KERNEL;	\
>>> +	if (regs->flags & PERF_EFLAGS_EXACT)		\
>>> +		misc |= PERF_RECORD_MISC_EXACT;		\
>>> +	misc; })
>>> +
>>> +#define perf_instruction_pointer(regs)	((regs)->ip)
>>
>> Hmm, why don't you use instruction_pointer() defined in asm/ptrace.h?
>> And I couldn't find any user of this macro in this patch...
> 
> perf_instruction_pointer() is used in kernel/perf_event.c, and yeah I
> could have used instruction_pointer() but that's yet another wrapper.
> 
> Anyway, Yanmin is poking at doing kvm-guest profiling and will likely
> rewrite all of the perf_misc() and perf_instruction_pointer() stuff
> soon.

Hmm, still I can't find where it is used (in your patches).
Anyway, would you mean that perf_instruction_pointer() will
have different implementation by Yanmin?

Thank you,

-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

[Masami Hiramatsu]

Masami Hiramatsu wrote:
> Peter Zijlstra wrote:
>> On Thu, 2010-03-04 at 11:21 -0500, Masami Hiramatsu wrote:
>>> Peter Zijlstra wrote:
>>
>>>> +#define perf_misc_flags(regs)				\
>>>> +({	int misc = 0;					\
>>>> +	if (user_mode(regs))				\
>>>> +		misc |= PERF_RECORD_MISC_USER;		\
>>>> +	else						\
>>>> +		misc |= PERF_RECORD_MISC_KERNEL;	\
>>>> +	if (regs->flags & PERF_EFLAGS_EXACT)		\
>>>> +		misc |= PERF_RECORD_MISC_EXACT;		\
>>>> +	misc; })
>>>> +
>>>> +#define perf_instruction_pointer(regs)	((regs)->ip)
>>>
>>> Hmm, why don't you use instruction_pointer() defined in asm/ptrace.h?
>>> And I couldn't find any user of this macro in this patch...
>>
>> perf_instruction_pointer() is used in kernel/perf_event.c, and yeah I
>> could have used instruction_pointer() but that's yet another wrapper.
>>
>> Anyway, Yanmin is poking at doing kvm-guest profiling and will likely
>> rewrite all of the perf_misc() and perf_instruction_pointer() stuff
>> soon.
> 
> Hmm, still I can't find where it is used (in your patches).

Ah, OK. that is already used in kernel/perf_event.c and
the patch overwrites one defined in include/linux/perf_event.h.

Reviewed-by: Masami Hiramatsu <mhiramat@redhat.com>

Thank you,


-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

Re: [PATCH 09/14] perf, x86: use LBR for PEBS IP+1 fixup

[Peter Zijlstra]

On Thu, 2010-03-04 at 15:54 -0500, Masami Hiramatsu wrote:

> Anyway, would you mean that perf_instruction_pointer() will
> have different implementation by Yanmin?

Yes, he will also be checking if we came from guest context:

http://www.mail-archive.com/kvm@vger.kernel.org/msg29830.html

[tip:perf/pebs] perf, x86: use LBR for PEBS IP+1 fixup

[tip-bot for Peter Zijlstra]

Commit-ID:  ef21f683a045a79b6aa86ad81e5fdfc0d5ddd250
Gitweb:     http://git.kernel.org/tip/ef21f683a045a79b6aa86ad81e5fdfc0d5ddd250
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 3 Mar 2010 13:12:23 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:32 +0100

perf, x86: use LBR for PEBS IP+1 fixup

Use the LBR to fix up the PEBS IP+1 issue.

As said, PEBS reports the next instruction, here we use the LBR to find
the last branch and from that construct the actual IP. If the IP matches
the LBR-TO, we use LBR-FROM, otherwise we use the LBR-TO address as the
beginning of the last basic block and decode forward.

Once we find a match to the current IP, we use the previous location.

This patch introduces a new ABI element: PERF_RECORD_MISC_EXACT, which
conveys that the reported IP (PERF_SAMPLE_IP) is the exact instruction
that caused the event (barring CPU errata).

The fixup can fail due to various reasons:

 1) LBR contains invalid data (quite possible)
 2) part of the basic block got paged out
 3) the reported IP isn't part of the basic block (see 1)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.619375431@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/perf_event.h         |   19 +++++++
 arch/x86/kernel/cpu/perf_event.c          |   70 ++++++++++++------------
 arch/x86/kernel/cpu/perf_event_intel.c    |    4 +-
 arch/x86/kernel/cpu/perf_event_intel_ds.c |   84 ++++++++++++++++++++++++++++-
 include/linux/perf_event.h                |    6 ++
 5 files changed, 144 insertions(+), 39 deletions(-)

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index db6109a..a9038c9 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -136,6 +136,25 @@ extern void perf_events_lapic_init(void);
 
 #define PERF_EVENT_INDEX_OFFSET			0
 
+/*
+ * Abuse bit 3 of the cpu eflags register to indicate proper PEBS IP fixups.
+ * This flag is otherwise unused and ABI specified to be 0, so nobody should
+ * care what we do with it.
+ */
+#define PERF_EFLAGS_EXACT	(1UL << 3)
+
+#define perf_misc_flags(regs)				\
+({	int misc = 0;					\
+	if (user_mode(regs))				\
+		misc |= PERF_RECORD_MISC_USER;		\
+	else						\
+		misc |= PERF_RECORD_MISC_KERNEL;	\
+	if (regs->flags & PERF_EFLAGS_EXACT)		\
+		misc |= PERF_RECORD_MISC_EXACT;		\
+	misc; })
+
+#define perf_instruction_pointer(regs)	((regs)->ip)
+
 #else
 static inline void init_hw_perf_events(void)		{ }
 static inline void perf_events_lapic_init(void)	{ }
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 1badff6..5cb4e8d 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -29,6 +29,41 @@
 #include <asm/stacktrace.h>
 #include <asm/nmi.h>
 
+/*
+ * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
+ */
+static unsigned long
+copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
+{
+	unsigned long offset, addr = (unsigned long)from;
+	int type = in_nmi() ? KM_NMI : KM_IRQ0;
+	unsigned long size, len = 0;
+	struct page *page;
+	void *map;
+	int ret;
+
+	do {
+		ret = __get_user_pages_fast(addr, 1, 0, &page);
+		if (!ret)
+			break;
+
+		offset = addr & (PAGE_SIZE - 1);
+		size = min(PAGE_SIZE - offset, n - len);
+
+		map = kmap_atomic(page, type);
+		memcpy(to, map+offset, size);
+		kunmap_atomic(map, type);
+		put_page(page);
+
+		len  += size;
+		to   += size;
+		addr += size;
+
+	} while (len < n);
+
+	return len;
+}
+
 static u64 perf_event_mask __read_mostly;
 
 struct event_constraint {
@@ -1550,41 +1585,6 @@ perf_callchain_kernel(struct pt_regs *regs, struct perf_callchain_entry *entry)
 	dump_trace(NULL, regs, NULL, regs->bp, &backtrace_ops, entry);
 }
 
-/*
- * best effort, GUP based copy_from_user() that assumes IRQ or NMI context
- */
-static unsigned long
-copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
-{
-	unsigned long offset, addr = (unsigned long)from;
-	int type = in_nmi() ? KM_NMI : KM_IRQ0;
-	unsigned long size, len = 0;
-	struct page *page;
-	void *map;
-	int ret;
-
-	do {
-		ret = __get_user_pages_fast(addr, 1, 0, &page);
-		if (!ret)
-			break;
-
-		offset = addr & (PAGE_SIZE - 1);
-		size = min(PAGE_SIZE - offset, n - len);
-
-		map = kmap_atomic(page, type);
-		memcpy(to, map+offset, size);
-		kunmap_atomic(map, type);
-		put_page(page);
-
-		len  += size;
-		to   += size;
-		addr += size;
-
-	} while (len < n);
-
-	return len;
-}
-
 static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
 {
 	unsigned long bytes;
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 44f6ed4..7eb78be 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -547,7 +547,7 @@ static void intel_pmu_disable_event(struct perf_event *event)
 	x86_pmu_disable_event(event);
 
 	if (unlikely(event->attr.precise))
-		intel_pmu_pebs_disable(hwc);
+		intel_pmu_pebs_disable(event);
 }
 
 static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
@@ -600,7 +600,7 @@ static void intel_pmu_enable_event(struct perf_event *event)
 	}
 
 	if (unlikely(event->attr.precise))
-		intel_pmu_pebs_enable(hwc);
+		intel_pmu_pebs_enable(event);
 
 	__x86_pmu_enable_event(hwc);
 }
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 0d994ef..50e6ff3 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -331,26 +331,32 @@ intel_pebs_constraints(struct perf_event *event)
 	return &emptyconstraint;
 }
 
-static void intel_pmu_pebs_enable(struct hw_perf_event *hwc)
+static void intel_pmu_pebs_enable(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val = cpuc->pebs_enabled;
 
 	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
 
 	val |= 1ULL << hwc->idx;
 	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
+
+	intel_pmu_lbr_enable(event);
 }
 
-static void intel_pmu_pebs_disable(struct hw_perf_event *hwc)
+static void intel_pmu_pebs_disable(struct perf_event *event)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct hw_perf_event *hwc = &event->hw;
 	u64 val = cpuc->pebs_enabled;
 
 	val &= ~(1ULL << hwc->idx);
 	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
 
 	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
+
+	intel_pmu_lbr_disable(event);
 }
 
 static void intel_pmu_pebs_enable_all(void)
@@ -369,6 +375,70 @@ static void intel_pmu_pebs_disable_all(void)
 		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
 }
 
+#include <asm/insn.h>
+
+#define MAX_INSN_SIZE	16
+
+static inline bool kernel_ip(unsigned long ip)
+{
+#ifdef CONFIG_X86_32
+	return ip > PAGE_OFFSET;
+#else
+	return (long)ip < 0;
+#endif
+}
+
+static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
+{
+	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	unsigned long from = cpuc->lbr_entries[0].from;
+	unsigned long old_to, to = cpuc->lbr_entries[0].to;
+	unsigned long ip = regs->ip;
+
+	if (!cpuc->lbr_stack.nr || !from || !to)
+		return 0;
+
+	if (ip < to)
+		return 0;
+
+	/*
+	 * We sampled a branch insn, rewind using the LBR stack
+	 */
+	if (ip == to) {
+		regs->ip = from;
+		return 1;
+	}
+
+	do {
+		struct insn insn;
+		u8 buf[MAX_INSN_SIZE];
+		void *kaddr;
+
+		old_to = to;
+		if (!kernel_ip(ip)) {
+			int bytes, size = min_t(int, MAX_INSN_SIZE, ip - to);
+
+			bytes = copy_from_user_nmi(buf, (void __user *)to, size);
+			if (bytes != size)
+				return 0;
+
+			kaddr = buf;
+		} else
+			kaddr = (void *)to;
+
+		kernel_insn_init(&insn, kaddr);
+		insn_get_length(&insn);
+		to += insn.length;
+	} while (to < ip);
+
+	if (to == ip) {
+		regs->ip = old_to;
+		return 1;
+	}
+
+	return 0;
+}
+
 static int intel_pmu_save_and_restart(struct perf_event *event);
 static void intel_pmu_disable_event(struct perf_event *event);
 
@@ -424,6 +494,11 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 	regs.bp = at->bp;
 	regs.sp = at->sp;
 
+	if (intel_pmu_pebs_fixup_ip(&regs))
+		regs.flags |= PERF_EFLAGS_EXACT;
+	else
+		regs.flags &= ~PERF_EFLAGS_EXACT;
+
 	if (perf_event_overflow(event, 1, &data, &regs))
 		intel_pmu_disable_event(event);
 
@@ -487,6 +562,11 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 		regs.bp = at->bp;
 		regs.sp = at->sp;
 
+		if (intel_pmu_pebs_fixup_ip(&regs))
+			regs.flags |= PERF_EFLAGS_EXACT;
+		else
+			regs.flags &= ~PERF_EFLAGS_EXACT;
+
 		if (perf_event_overflow(event, 1, &data, &regs))
 			intel_pmu_disable_event(event);
 	}
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index ab4fd9e..be85f7c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -294,6 +294,12 @@ struct perf_event_mmap_page {
 #define PERF_RECORD_MISC_USER			(2 << 0)
 #define PERF_RECORD_MISC_HYPERVISOR		(3 << 0)
 
+#define PERF_RECORD_MISC_EXACT			(1 << 14)
+/*
+ * Reserve the last bit to indicate some extended misc field
+ */
+#define PERF_RECORD_MISC_EXT_RESERVED		(1 << 15)
+
 struct perf_event_header {
 	__u32	type;
 	__u16	misc;

[PATCH 10/14] perf-top: Show the percentage of successfull PEBS-fixups

[Peter Zijlstra]

[-- Attachment #1: perf-tools-exact.patch --]
[-- Type: text/plain, Size: 2243 bytes --]

Use the PERF_RECORD_MISC_EXACT information to measure the success
rate of the PEBS fix-up.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 tools/perf/builtin-top.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Index: linux-2.6/tools/perf/builtin-top.c
===================================================================
--- linux-2.6.orig/tools/perf/builtin-top.c
+++ linux-2.6/tools/perf/builtin-top.c
@@ -410,6 +410,7 @@ static double sym_weight(const struct sy
 
 static long			samples;
 static long			userspace_samples;
+static long			exact_samples;
 static const char		CONSOLE_CLEAR[] = "^[[H^[[2J";
 
 static void __list_insert_active_sym(struct sym_entry *syme)
@@ -450,6 +451,7 @@ static void print_sym_table(void)
 	int counter, snap = !display_weighted ? sym_counter : 0;
 	float samples_per_sec = samples/delay_secs;
 	float ksamples_per_sec = (samples-userspace_samples)/delay_secs;
+	float esamples_percent = (100.0*exact_samples)/samples;
 	float sum_ksamples = 0.0;
 	struct sym_entry *syme, *n;
 	struct rb_root tmp = RB_ROOT;
@@ -457,7 +459,7 @@ static void print_sym_table(void)
 	int sym_width = 0, dso_width = 0, max_dso_width;
 	const int win_width = winsize.ws_col - 1;
 
-	samples = userspace_samples = 0;
+	samples = userspace_samples = exact_samples = 0;
 
 	/* Sort the active symbols */
 	pthread_mutex_lock(&active_symbols_lock);
@@ -488,9 +490,10 @@ static void print_sym_table(void)
 	puts(CONSOLE_CLEAR);
 
 	printf("%-*.*s\n", win_width, win_width, graph_dotted_line);
-	printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%% [",
+	printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%%  exact: %4.1f%% [",
 		samples_per_sec,
-		100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)));
+		100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)),
+		esamples_percent);
 
 	if (nr_counters == 1 || !display_weighted) {
 		printf("%Ld", (u64)attrs[0].sample_period);
@@ -954,6 +957,9 @@ static void event__process_sample(const 
 		return;
 	}
 
+	if (self->header.misc & PERF_RECORD_MISC_EXACT)
+		exact_samples++;
+
 	if (event__preprocess_sample(self, session, &al, symbol_filter) < 0 ||
 	    al.filtered)
 		return;

-- 

[tip:perf/pebs] perf-top: Show the percentage of successfull PEBS-fixups

[tip-bot for Peter Zijlstra]

Commit-ID:  1676b8a077c352085d52578fb4f29350b58b6e74
Gitweb:     http://git.kernel.org/tip/1676b8a077c352085d52578fb4f29350b58b6e74
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 4 Mar 2010 14:19:36 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:33 +0100

perf-top: Show the percentage of successfull PEBS-fixups

Use the PERF_RECORD_MISC_EXACT information to measure the success rate of
the PEBS fix-up.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.694233760@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 tools/perf/builtin-top.c |   12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 31f2e59..c051833 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -410,6 +410,7 @@ static double sym_weight(const struct sym_entry *sym)
 
 static long			samples;
 static long			userspace_samples;
+static long			exact_samples;
 static const char		CONSOLE_CLEAR[] = "^[[H^[[2J";
 
 static void __list_insert_active_sym(struct sym_entry *syme)
@@ -450,6 +451,7 @@ static void print_sym_table(void)
 	int counter, snap = !display_weighted ? sym_counter : 0;
 	float samples_per_sec = samples/delay_secs;
 	float ksamples_per_sec = (samples-userspace_samples)/delay_secs;
+	float esamples_percent = (100.0*exact_samples)/samples;
 	float sum_ksamples = 0.0;
 	struct sym_entry *syme, *n;
 	struct rb_root tmp = RB_ROOT;
@@ -457,7 +459,7 @@ static void print_sym_table(void)
 	int sym_width = 0, dso_width = 0, max_dso_width;
 	const int win_width = winsize.ws_col - 1;
 
-	samples = userspace_samples = 0;
+	samples = userspace_samples = exact_samples = 0;
 
 	/* Sort the active symbols */
 	pthread_mutex_lock(&active_symbols_lock);
@@ -488,9 +490,10 @@ static void print_sym_table(void)
 	puts(CONSOLE_CLEAR);
 
 	printf("%-*.*s\n", win_width, win_width, graph_dotted_line);
-	printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%% [",
+	printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%%  exact: %4.1f%% [",
 		samples_per_sec,
-		100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)));
+		100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)),
+		esamples_percent);
 
 	if (nr_counters == 1 || !display_weighted) {
 		printf("%Ld", (u64)attrs[0].sample_period);
@@ -954,6 +957,9 @@ static void event__process_sample(const event_t *self,
 		return;
 	}
 
+	if (self->header.misc & PERF_RECORD_MISC_EXACT)
+		exact_samples++;
+
 	if (event__preprocess_sample(self, session, &al, symbol_filter) < 0 ||
 	    al.filtered)
 		return;

[PATCH 11/14] perf, x86: Clean up IA32_PERF_CAPABILITIES usage

[Peter Zijlstra]

[-- Attachment #1: perf-capabilities.patch --]
[-- Type: text/plain, Size: 6924 bytes --]

Saner PERF_CAPABILITIES support, which also exposes pebs_trap. Use that
latter to make PEBS's use of LBR conditional since a fault-like pebs
should already report the correct IP.

(As of this writing there is no known hardware that implements !pebs_trap)

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c           |   15 ++++++++++++--
 arch/x86/kernel/cpu/perf_event_intel.c     |   10 +++++++++
 arch/x86/kernel/cpu/perf_event_intel_ds.c  |   30 ++++++++++++++---------------
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |   18 +++--------------
 4 files changed, 42 insertions(+), 31 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -154,6 +154,17 @@ struct cpu_hw_events {
 #define for_each_event_constraint(e, c)	\
 	for ((e) = (c); (e)->cmask; (e)++)
 
+union perf_capabilities {
+	struct {
+		u64	lbr_format    : 6;
+		u64	pebs_trap     : 1;
+		u64	pebs_arch_reg : 1;
+		u64	pebs_format   : 4;
+		u64	smm_freeze    : 1;
+	};
+	u64	capabilities;
+};
+
 /*
  * struct x86_pmu - generic x86 pmu
  */
@@ -190,7 +201,8 @@ struct x86_pmu {
 	/*
 	 * Intel Arch Perfmon v2+
 	 */
-	u64		intel_ctrl;
+	u64			intel_ctrl;
+	union perf_capabilities intel_cap;
 
 	/*
 	 * Intel DebugStore bits
@@ -205,7 +217,6 @@ struct x86_pmu {
 	 */
 	unsigned long	lbr_tos, lbr_from, lbr_to; /* MSR base regs       */
 	int		lbr_nr;			   /* hardware stack size */
-	int		lbr_format;		   /* hardware format     */
 };
 
 static struct x86_pmu x86_pmu __read_mostly;
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -834,6 +834,16 @@ static __init int intel_pmu_init(void)
 	if (version > 1)
 		x86_pmu.num_events_fixed = max((int)edx.split.num_events_fixed, 3);
 
+	/*
+	 * v2 and above have a perf capabilities MSR
+	 */
+	if (version > 1) {
+		u64 capabilities;
+
+		rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
+		x86_pmu.intel_cap.capabilities = capabilities;
+	}
+
 	intel_ds_init();
 
 	/*
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -342,7 +342,8 @@ static void intel_pmu_pebs_enable(struct
 	val |= 1ULL << hwc->idx;
 	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
 
-	intel_pmu_lbr_enable(event);
+	if (x86_pmu.intel_cap.pebs_trap)
+		intel_pmu_lbr_enable(event);
 }
 
 static void intel_pmu_pebs_disable(struct perf_event *event)
@@ -356,7 +357,8 @@ static void intel_pmu_pebs_disable(struc
 
 	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
 
-	intel_pmu_lbr_disable(event);
+	if (x86_pmu.intel_cap.pebs_trap)
+		intel_pmu_lbr_disable(event);
 }
 
 static void intel_pmu_pebs_enable_all(void)
@@ -395,6 +397,12 @@ static int intel_pmu_pebs_fixup_ip(struc
 	unsigned long old_to, to = cpuc->lbr_entries[0].to;
 	unsigned long ip = regs->ip;
 
+	/*
+	 * We don't need to fixup if the PEBS assist is fault like
+	 */
+	if (!x86_pmu.intel_cap.pebs_trap)
+		return 1;
+
 	if (!cpuc->lbr_stack.nr || !from || !to)
 		return 0;
 
@@ -599,34 +607,26 @@ static void intel_ds_init(void)
 	x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
 	x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
 	if (x86_pmu.pebs) {
-		int format = 0;
-
-		if (x86_pmu.version > 1) {
-			u64 capabilities;
-			/*
-			 * v2+ has a PEBS format field
-			 */
-			rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
-			format = (capabilities >> 8) & 0xf;
-		}
+		char pebs_type = x86_pmu.intel_cap.pebs_trap ?  '+' : '-';
+		int format = x86_pmu.intel_cap.pebs_format;
 
 		switch (format) {
 		case 0:
-			printk(KERN_CONT "PEBS v0, ");
+			printk(KERN_CONT "PEBS fmt0%c, ", pebs_type);
 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
 			x86_pmu.pebs_constraints = intel_core_pebs_events;
 			break;
 
 		case 1:
-			printk(KERN_CONT "PEBS v1, ");
+			printk(KERN_CONT "PEBS fmt1%c, ", pebs_type);
 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
 			x86_pmu.pebs_constraints = intel_nehalem_pebs_events;
 			break;
 
 		default:
-			printk(KERN_CONT "PEBS unknown format: %d, ", format);
+			printk(KERN_CONT "no PEBS fmt%d%c, ", format, pebs_type);
 			x86_pmu.pebs = 0;
 			break;
 		}
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_lbr.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -53,7 +53,7 @@ static void intel_pmu_lbr_reset_64(void)
 
 static void intel_pmu_lbr_reset(void)
 {
-	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+	if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
 		intel_pmu_lbr_reset_32();
 	else
 		intel_pmu_lbr_reset_64();
@@ -155,6 +155,7 @@ static void intel_pmu_lbr_read_32(struct
 static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
 {
 	unsigned long mask = x86_pmu.lbr_nr - 1;
+	int lbr_format = x86_pmu.intel_cap.lbr_format;
 	u64 tos = intel_pmu_lbr_tos();
 	int i;
 
@@ -165,7 +166,7 @@ static void intel_pmu_lbr_read_64(struct
 		rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
 		rdmsrl(x86_pmu.lbr_to   + lbr_idx, to);
 
-		if (x86_pmu.lbr_format == LBR_FORMAT_EIP_FLAGS) {
+		if (lbr_format == LBR_FORMAT_EIP_FLAGS) {
 			flags = !!(from & LBR_FROM_FLAG_MISPRED);
 			from = (u64)((((s64)from) << 1) >> 1);
 		}
@@ -184,23 +185,14 @@ static void intel_pmu_lbr_read(void)
 	if (!cpuc->lbr_users)
 		return;
 
-	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+	if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
 		intel_pmu_lbr_read_32(cpuc);
 	else
 		intel_pmu_lbr_read_64(cpuc);
 }
 
-static int intel_pmu_lbr_format(void)
-{
-	u64 capabilities;
-
-	rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
-	return capabilities & 0x1f;
-}
-
 static void intel_pmu_lbr_init_core(void)
 {
-	x86_pmu.lbr_format = intel_pmu_lbr_format();
 	x86_pmu.lbr_nr     = 4;
 	x86_pmu.lbr_tos    = 0x01c9;
 	x86_pmu.lbr_from   = 0x40;
@@ -209,7 +201,6 @@ static void intel_pmu_lbr_init_core(void
 
 static void intel_pmu_lbr_init_nhm(void)
 {
-	x86_pmu.lbr_format = intel_pmu_lbr_format();
 	x86_pmu.lbr_nr     = 16;
 	x86_pmu.lbr_tos    = 0x01c9;
 	x86_pmu.lbr_from   = 0x680;
@@ -218,7 +209,6 @@ static void intel_pmu_lbr_init_nhm(void)
 
 static void intel_pmu_lbr_init_atom(void)
 {
-	x86_pmu.lbr_format = intel_pmu_lbr_format();
 	x86_pmu.lbr_nr	   = 8;
 	x86_pmu.lbr_tos    = 0x01c9;
 	x86_pmu.lbr_from   = 0x40;

-- 

[tip:perf/pebs] perf, x86: Clean up IA32_PERF_CAPABILITIES usage

[tip-bot for Peter Zijlstra]

Commit-ID:  8db909a7e3c888b5d45aef7650d74ccebe3ce725
Gitweb:     http://git.kernel.org/tip/8db909a7e3c888b5d45aef7650d74ccebe3ce725
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 3 Mar 2010 17:07:40 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:33 +0100

perf, x86: Clean up IA32_PERF_CAPABILITIES usage

Saner PERF_CAPABILITIES support, which also exposes pebs_trap. Use that
latter to make PEBS's use of LBR conditional since a fault-like pebs
should already report the correct IP.

( As of this writing there is no known hardware that implements
  !pebs_trap )

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.770650663@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c           |   15 ++++++++++++-
 arch/x86/kernel/cpu/perf_event_intel.c     |   10 +++++++++
 arch/x86/kernel/cpu/perf_event_intel_ds.c  |   30 ++++++++++++++--------------
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |   18 +++-------------
 4 files changed, 42 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 5cb4e8d..7b5430b 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -154,6 +154,17 @@ struct cpu_hw_events {
 #define for_each_event_constraint(e, c)	\
 	for ((e) = (c); (e)->cmask; (e)++)
 
+union perf_capabilities {
+	struct {
+		u64	lbr_format    : 6;
+		u64	pebs_trap     : 1;
+		u64	pebs_arch_reg : 1;
+		u64	pebs_format   : 4;
+		u64	smm_freeze    : 1;
+	};
+	u64	capabilities;
+};
+
 /*
  * struct x86_pmu - generic x86 pmu
  */
@@ -195,7 +206,8 @@ struct x86_pmu {
 	/*
 	 * Intel Arch Perfmon v2+
 	 */
-	u64		intel_ctrl;
+	u64			intel_ctrl;
+	union perf_capabilities intel_cap;
 
 	/*
 	 * Intel DebugStore bits
@@ -210,7 +222,6 @@ struct x86_pmu {
 	 */
 	unsigned long	lbr_tos, lbr_from, lbr_to; /* MSR base regs       */
 	int		lbr_nr;			   /* hardware stack size */
-	int		lbr_format;		   /* hardware format     */
 };
 
 static struct x86_pmu x86_pmu __read_mostly;
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 7eb78be..246c072 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -835,6 +835,16 @@ static __init int intel_pmu_init(void)
 	if (version > 1)
 		x86_pmu.num_events_fixed = max((int)edx.split.num_events_fixed, 3);
 
+	/*
+	 * v2 and above have a perf capabilities MSR
+	 */
+	if (version > 1) {
+		u64 capabilities;
+
+		rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
+		x86_pmu.intel_cap.capabilities = capabilities;
+	}
+
 	intel_ds_init();
 
 	/*
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 50e6ff3..5e40294 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -342,7 +342,8 @@ static void intel_pmu_pebs_enable(struct perf_event *event)
 	val |= 1ULL << hwc->idx;
 	wrmsrl(MSR_IA32_PEBS_ENABLE, val);
 
-	intel_pmu_lbr_enable(event);
+	if (x86_pmu.intel_cap.pebs_trap)
+		intel_pmu_lbr_enable(event);
 }
 
 static void intel_pmu_pebs_disable(struct perf_event *event)
@@ -356,7 +357,8 @@ static void intel_pmu_pebs_disable(struct perf_event *event)
 
 	hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
 
-	intel_pmu_lbr_disable(event);
+	if (x86_pmu.intel_cap.pebs_trap)
+		intel_pmu_lbr_disable(event);
 }
 
 static void intel_pmu_pebs_enable_all(void)
@@ -395,6 +397,12 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
 	unsigned long old_to, to = cpuc->lbr_entries[0].to;
 	unsigned long ip = regs->ip;
 
+	/*
+	 * We don't need to fixup if the PEBS assist is fault like
+	 */
+	if (!x86_pmu.intel_cap.pebs_trap)
+		return 1;
+
 	if (!cpuc->lbr_stack.nr || !from || !to)
 		return 0;
 
@@ -589,34 +597,26 @@ static void intel_ds_init(void)
 	x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
 	x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
 	if (x86_pmu.pebs) {
-		int format = 0;
-
-		if (x86_pmu.version > 1) {
-			u64 capabilities;
-			/*
-			 * v2+ has a PEBS format field
-			 */
-			rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
-			format = (capabilities >> 8) & 0xf;
-		}
+		char pebs_type = x86_pmu.intel_cap.pebs_trap ?  '+' : '-';
+		int format = x86_pmu.intel_cap.pebs_format;
 
 		switch (format) {
 		case 0:
-			printk(KERN_CONT "PEBS v0, ");
+			printk(KERN_CONT "PEBS fmt0%c, ", pebs_type);
 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
 			x86_pmu.pebs_constraints = intel_core_pebs_events;
 			break;
 
 		case 1:
-			printk(KERN_CONT "PEBS v1, ");
+			printk(KERN_CONT "PEBS fmt1%c, ", pebs_type);
 			x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
 			x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
 			x86_pmu.pebs_constraints = intel_nehalem_pebs_events;
 			break;
 
 		default:
-			printk(KERN_CONT "PEBS unknown format: %d, ", format);
+			printk(KERN_CONT "no PEBS fmt%d%c, ", format, pebs_type);
 			x86_pmu.pebs = 0;
 			break;
 		}
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index ea3e99e..4f3a124 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -53,7 +53,7 @@ static void intel_pmu_lbr_reset_64(void)
 
 static void intel_pmu_lbr_reset(void)
 {
-	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+	if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
 		intel_pmu_lbr_reset_32();
 	else
 		intel_pmu_lbr_reset_64();
@@ -155,6 +155,7 @@ static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
 static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
 {
 	unsigned long mask = x86_pmu.lbr_nr - 1;
+	int lbr_format = x86_pmu.intel_cap.lbr_format;
 	u64 tos = intel_pmu_lbr_tos();
 	int i;
 
@@ -165,7 +166,7 @@ static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc)
 		rdmsrl(x86_pmu.lbr_from + lbr_idx, from);
 		rdmsrl(x86_pmu.lbr_to   + lbr_idx, to);
 
-		if (x86_pmu.lbr_format == LBR_FORMAT_EIP_FLAGS) {
+		if (lbr_format == LBR_FORMAT_EIP_FLAGS) {
 			flags = !!(from & LBR_FROM_FLAG_MISPRED);
 			from = (u64)((((s64)from) << 1) >> 1);
 		}
@@ -184,23 +185,14 @@ static void intel_pmu_lbr_read(void)
 	if (!cpuc->lbr_users)
 		return;
 
-	if (x86_pmu.lbr_format == LBR_FORMAT_32)
+	if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
 		intel_pmu_lbr_read_32(cpuc);
 	else
 		intel_pmu_lbr_read_64(cpuc);
 }
 
-static int intel_pmu_lbr_format(void)
-{
-	u64 capabilities;
-
-	rdmsrl(MSR_IA32_PERF_CAPABILITIES, capabilities);
-	return capabilities & 0x1f;
-}
-
 static void intel_pmu_lbr_init_core(void)
 {
-	x86_pmu.lbr_format = intel_pmu_lbr_format();
 	x86_pmu.lbr_nr     = 4;
 	x86_pmu.lbr_tos    = 0x01c9;
 	x86_pmu.lbr_from   = 0x40;
@@ -209,7 +201,6 @@ static void intel_pmu_lbr_init_core(void)
 
 static void intel_pmu_lbr_init_nhm(void)
 {
-	x86_pmu.lbr_format = intel_pmu_lbr_format();
 	x86_pmu.lbr_nr     = 16;
 	x86_pmu.lbr_tos    = 0x01c9;
 	x86_pmu.lbr_from   = 0x680;
@@ -218,7 +209,6 @@ static void intel_pmu_lbr_init_nhm(void)
 
 static void intel_pmu_lbr_init_atom(void)
 {
-	x86_pmu.lbr_format = intel_pmu_lbr_format();
 	x86_pmu.lbr_nr	   = 8;
 	x86_pmu.lbr_tos    = 0x01c9;
 	x86_pmu.lbr_from   = 0x40;

[PATCH 12/14] perf, x86: Expose the full PEBS record using PERF_SAMPLE_RAW

[Peter Zijlstra]

[-- Attachment #1: perf-pebs-raw.patch --]
[-- Type: text/plain, Size: 1679 bytes --]

Expose the full PEBS record using PERF_SAMPLE_RAW

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event_intel_ds.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -457,6 +457,7 @@ static void intel_pmu_drain_pebs_core(st
 	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 	struct pebs_record_core *at, *top;
 	struct perf_sample_data data;
+	struct perf_raw_record raw;
 	struct pt_regs regs;
 	int n;
 
@@ -490,6 +491,12 @@ static void intel_pmu_drain_pebs_core(st
 		at += n-1;
 	}
 
+	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
+		raw.size = x86_pmu.pebs_record_size;
+		raw.data = at;
+		data.raw = &raw;
+	}
+
 	/*
 	 * We use the interrupt regs as a base because the PEBS record
 	 * does not contain a full regs set, specifically it seems to
@@ -524,6 +531,7 @@ static void intel_pmu_drain_pebs_nhm(str
 	struct pebs_record_nhm *at, *top;
 	struct perf_sample_data data;
 	struct perf_event *event = NULL;
+	struct perf_raw_record raw;
 	struct pt_regs regs;
 	int bit, n;
 
@@ -572,6 +580,12 @@ static void intel_pmu_drain_pebs_nhm(str
 		perf_sample_data_init(&data, 0);
 		data.period = event->hw.last_period;
 
+		if (event->attr.sample_type & PERF_SAMPLE_RAW) {
+			raw.size = x86_pmu.pebs_record_size;
+			raw.data = at;
+			data.raw = &raw;
+		}
+
 		/*
 		 * See the comment in intel_pmu_drain_pebs_core()
 		 */

-- 

[tip:perf/pebs] perf, x86: Expose the full PEBS record using PERF_SAMPLE_RAW

[tip-bot for Peter Zijlstra]

Commit-ID:  7e1a40dda619b0483fbe0740494ed2c2a1f05289
Gitweb:     http://git.kernel.org/tip/7e1a40dda619b0483fbe0740494ed2c2a1f05289
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 4 Mar 2010 12:38:03 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:33 +0100

perf, x86: Expose the full PEBS record using PERF_SAMPLE_RAW

Expose the full PEBS record using PERF_SAMPLE_RAW

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.847218224@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event_intel_ds.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 5e40294..ef56f05 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -457,6 +457,7 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 	struct pebs_record_core *at, *top;
 	struct perf_sample_data data;
+	struct perf_raw_record raw;
 	struct pt_regs regs;
 	int n;
 
@@ -479,6 +480,12 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 	perf_sample_data_init(&data, 0);
 	data.period = event->hw.last_period;
 
+	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
+		raw.size = x86_pmu.pebs_record_size;
+		raw.data = at;
+		data.raw = &raw;
+	}
+
 	n = top - at;
 
 	/*
@@ -521,6 +528,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 	struct pebs_record_nhm *at, *top;
 	struct perf_sample_data data;
 	struct perf_event *event = NULL;
+	struct perf_raw_record raw;
 	struct pt_regs regs;
 	int bit, n;
 
@@ -562,6 +570,12 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 		perf_sample_data_init(&data, 0);
 		data.period = event->hw.last_period;
 
+		if (event->attr.sample_type & PERF_SAMPLE_RAW) {
+			raw.size = x86_pmu.pebs_record_size;
+			raw.data = at;
+			data.raw = &raw;
+		}
+
 		/*
 		 * See the comment in intel_pmu_drain_pebs_core()
 		 */

[PATCH 13/14] x86: Move MAX_INSN_SIZE into asm/insn.h

[Peter Zijlstra]

[-- Attachment #1: x86-collect-max_insn_size.patch --]
[-- Type: text/plain, Size: 1984 bytes --]

Since there's now two users for this, place it in a common header.

CC: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/include/asm/insn.h               |    2 ++
 arch/x86/include/asm/kprobes.h            |    2 +-
 arch/x86/kernel/cpu/perf_event_intel_ds.c |    2 --
 3 files changed, 3 insertions(+), 3 deletions(-)

Index: linux-2.6/arch/x86/include/asm/insn.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/insn.h
+++ linux-2.6/arch/x86/include/asm/insn.h
@@ -68,6 +68,8 @@ struct insn {
 	const insn_byte_t *next_byte;
 };
 
+#define MAX_INSN_SIZE	16
+
 #define X86_MODRM_MOD(modrm) (((modrm) & 0xc0) >> 6)
 #define X86_MODRM_REG(modrm) (((modrm) & 0x38) >> 3)
 #define X86_MODRM_RM(modrm) ((modrm) & 0x07)
Index: linux-2.6/arch/x86/include/asm/kprobes.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/kprobes.h
+++ linux-2.6/arch/x86/include/asm/kprobes.h
@@ -24,6 +24,7 @@
 #include <linux/types.h>
 #include <linux/ptrace.h>
 #include <linux/percpu.h>
+#include <asm/insn.h>
 
 #define  __ARCH_WANT_KPROBES_INSN_SLOT
 
@@ -36,7 +37,6 @@ typedef u8 kprobe_opcode_t;
 #define RELATIVEJUMP_SIZE 5
 #define RELATIVECALL_OPCODE 0xe8
 #define RELATIVE_ADDR_SIZE 4
-#define MAX_INSN_SIZE 16
 #define MAX_STACK_SIZE 64
 #define MIN_STACK_SIZE(ADDR)					       \
 	(((MAX_STACK_SIZE) < (((unsigned long)current_thread_info()) + \
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -379,8 +379,6 @@ static void intel_pmu_pebs_disable_all(v
 
 #include <asm/insn.h>
 
-#define MAX_INSN_SIZE	16
-
 static inline bool kernel_ip(unsigned long ip)
 {
 #ifdef CONFIG_X86_32

-- 

Re: [PATCH 13/14] x86: Move MAX_INSN_SIZE into asm/insn.h

[Masami Hiramatsu]

Peter Zijlstra wrote:
> Since there's now two users for this, place it in a common header.
> 
> CC: Masami Hiramatsu <mhiramat@redhat.com>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> LKML-Reference: <new-submission>

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

Thank you,


-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

[tip:perf/pebs] x86: Move MAX_INSN_SIZE into asm/insn.h

[tip-bot for Peter Zijlstra]

Commit-ID:  30a813ae035d3e220a89609adce878e045c49547
Gitweb:     http://git.kernel.org/tip/30a813ae035d3e220a89609adce878e045c49547
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Thu, 4 Mar 2010 13:49:21 +0100
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 10 Mar 2010 13:23:34 +0100

x86: Move MAX_INSN_SIZE into asm/insn.h

Since there's now two users for this, place it in a common header.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.923774125@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/include/asm/insn.h               |    2 ++
 arch/x86/include/asm/kprobes.h            |    2 +-
 arch/x86/kernel/cpu/perf_event_intel_ds.c |    2 --
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 96c2e0a..88c765e 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -68,6 +68,8 @@ struct insn {
 	const insn_byte_t *next_byte;
 };
 
+#define MAX_INSN_SIZE	16
+
 #define X86_MODRM_MOD(modrm) (((modrm) & 0xc0) >> 6)
 #define X86_MODRM_REG(modrm) (((modrm) & 0x38) >> 3)
 #define X86_MODRM_RM(modrm) ((modrm) & 0x07)
diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h
index 4ffa345..5478825 100644
--- a/arch/x86/include/asm/kprobes.h
+++ b/arch/x86/include/asm/kprobes.h
@@ -24,6 +24,7 @@
 #include <linux/types.h>
 #include <linux/ptrace.h>
 #include <linux/percpu.h>
+#include <asm/insn.h>
 
 #define  __ARCH_WANT_KPROBES_INSN_SLOT
 
@@ -36,7 +37,6 @@ typedef u8 kprobe_opcode_t;
 #define RELATIVEJUMP_SIZE 5
 #define RELATIVECALL_OPCODE 0xe8
 #define RELATIVE_ADDR_SIZE 4
-#define MAX_INSN_SIZE 16
 #define MAX_STACK_SIZE 64
 #define MIN_STACK_SIZE(ADDR)					       \
 	(((MAX_STACK_SIZE) < (((unsigned long)current_thread_info()) + \
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index ef56f05..72453ac 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -379,8 +379,6 @@ static void intel_pmu_pebs_disable_all(void)
 
 #include <asm/insn.h>
 
-#define MAX_INSN_SIZE	16
-
 static inline bool kernel_ip(unsigned long ip)
 {
 #ifdef CONFIG_X86_32

[PATCH 14/14] perf, x86: Implement PERF_SAMPLE_BRANCH_STACK

[Peter Zijlstra]

[-- Attachment #1: perf-sample-lbr.patch --]
[-- Type: text/plain, Size: 8845 bytes --]

Not for merging until there's a sensible use case implemented in
tools/perf as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
---
 arch/x86/kernel/cpu/perf_event.c           |    3 +-
 arch/x86/kernel/cpu/perf_event_intel.c     |   10 ++++++-
 arch/x86/kernel/cpu/perf_event_intel_ds.c  |   20 ++++++---------
 arch/x86/kernel/cpu/perf_event_intel_lbr.c |    4 ++-
 include/linux/perf_event.h                 |   15 ++++++++---
 kernel/perf_event.c                        |   38 ++++++++++++++++++++++-------
 6 files changed, 62 insertions(+), 28 deletions(-)

Index: linux-2.6/include/linux/perf_event.h
===================================================================
--- linux-2.6.orig/include/linux/perf_event.h
+++ linux-2.6/include/linux/perf_event.h
@@ -125,8 +125,9 @@ enum perf_event_sample_format {
 	PERF_SAMPLE_PERIOD			= 1U << 8,
 	PERF_SAMPLE_STREAM_ID			= 1U << 9,
 	PERF_SAMPLE_RAW				= 1U << 10,
+	PERF_SAMPLE_BRANCH_STACK		= 1U << 11,
 
-	PERF_SAMPLE_MAX = 1U << 11,		/* non-ABI */
+	PERF_SAMPLE_MAX = 1U << 12,		/* non-ABI */
 };
 
 /*
@@ -399,9 +400,13 @@ enum perf_event_type {
 	 *
 	 *	{ struct read_format	values;	  } && PERF_SAMPLE_READ
 	 *
-	 *	{ u64			nr,
+	 *	{ u64			nr;
 	 *	  u64			ips[nr];  } && PERF_SAMPLE_CALLCHAIN
 	 *
+	 * 	{ u64			nr;
+	 * 	  { u64 from, to, flags;
+	 * 	  }			lbr[nr];  } && PERF_SAMPLE_BRANCH_STACK
+	 *
 	 *	#
 	 *	# The RAW record below is opaque data wrt the ABI
 	 *	#
@@ -817,13 +822,15 @@ struct perf_sample_data {
 	u64				period;
 	struct perf_callchain_entry	*callchain;
 	struct perf_raw_record		*raw;
+	struct perf_branch_stack	*branches;
 };
 
 static inline
 void perf_sample_data_init(struct perf_sample_data *data, u64 addr)
 {
-	data->addr = addr;
-	data->raw  = NULL;
+	data->addr     = addr;
+	data->raw      = NULL;
+	data->branches = NULL;
 }
 
 extern void perf_output_sample(struct perf_output_handle *handle,
Index: linux-2.6/kernel/perf_event.c
===================================================================
--- linux-2.6.orig/kernel/perf_event.c
+++ linux-2.6/kernel/perf_event.c
@@ -3178,12 +3178,9 @@ void perf_output_sample(struct perf_outp
 
 	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
 		if (data->callchain) {
-			int size = 1;
+			int size = sizeof(u64);
 
-			if (data->callchain)
-				size += data->callchain->nr;
-
-			size *= sizeof(u64);
+			size += data->callchain->nr * sizeof(u64);
 
 			perf_output_copy(handle, data->callchain, size);
 		} else {
@@ -3192,6 +3189,20 @@ void perf_output_sample(struct perf_outp
 		}
 	}
 
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
+		if (data->branches) {
+			int size = sizeof(u64);
+
+			size += data->branches->nr *
+				sizeof(struct perf_branch_entry);
+
+			perf_output_copy(handle, data->branches, size);
+		} else {
+			u64 nr = 0;
+			perf_output_put(handle, nr);
+		}
+	}
+
 	if (sample_type & PERF_SAMPLE_RAW) {
 		if (data->raw) {
 			perf_output_put(handle, data->raw->size);
@@ -3274,14 +3285,25 @@ void perf_prepare_sample(struct perf_eve
 		header->size += perf_event_read_size(event);
 
 	if (sample_type & PERF_SAMPLE_CALLCHAIN) {
-		int size = 1;
+		int size = sizeof(u64);
 
 		data->callchain = perf_callchain(regs);
 
 		if (data->callchain)
-			size += data->callchain->nr;
+			size += data->callchain->nr * sizeof(u64);
+
+		header->size += size;
+	}
 
-		header->size += size * sizeof(u64);
+	if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
+		int size = sizeof(u64);
+
+		if (data->branches) {
+			size += data->branches->nr *
+				sizeof(struct perf_branch_entry);
+		}
+
+		header->size += size;
 	}
 
 	if (sample_type & PERF_SAMPLE_RAW) {
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c
@@ -548,6 +548,9 @@ static void intel_pmu_disable_event(stru
 
 	if (unlikely(event->attr.precise))
 		intel_pmu_pebs_disable(event);
+
+	if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK)
+		intel_pmu_lbr_disable(event);
 }
 
 static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
@@ -602,6 +605,9 @@ static void intel_pmu_enable_event(struc
 	if (unlikely(event->attr.precise))
 		intel_pmu_pebs_enable(event);
 
+	if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK)
+		intel_pmu_lbr_enable(event);
+
 	__x86_pmu_enable_event(hwc);
 }
 
@@ -677,13 +683,13 @@ again:
 	inc_irq_stat(apic_perf_irqs);
 	ack = status;
 
-	intel_pmu_lbr_read();
+	intel_pmu_lbr_read(&data);
 
 	/*
 	 * PEBS overflow sets bit 62 in the global status register
 	 */
 	if (__test_and_clear_bit(62, (unsigned long *)&status))
-		x86_pmu.drain_pebs(regs);
+		x86_pmu.drain_pebs(&data, regs);
 
 	for_each_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
 		struct perf_event *event = cpuc->events[bit];
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -448,13 +448,12 @@ static int intel_pmu_pebs_fixup_ip(struc
 static int intel_pmu_save_and_restart(struct perf_event *event);
 static void intel_pmu_disable_event(struct perf_event *event);
 
-static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
+static void intel_pmu_drain_pebs_core(struct perf_sample_data *data, struct pt_regs *iregs)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 	struct pebs_record_core *at, *top;
-	struct perf_sample_data data;
 	struct perf_raw_record raw;
 	struct pt_regs regs;
 	int n;
@@ -475,8 +474,7 @@ static void intel_pmu_drain_pebs_core(st
 	if (!intel_pmu_save_and_restart(event))
 		goto out;
 
-	perf_sample_data_init(&data, 0);
-	data.period = event->hw.last_period;
+	data->period = event->hw.last_period;
 
 	n = top - at;
 
@@ -492,7 +490,7 @@ static void intel_pmu_drain_pebs_core(st
 	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
 		raw.size = x86_pmu.pebs_record_size;
 		raw.data = at;
-		data.raw = &raw;
+		data->raw = &raw;
 	}
 
 	/*
@@ -515,19 +513,18 @@ static void intel_pmu_drain_pebs_core(st
 	else
 		regs.flags &= ~PERF_EFLAGS_EXACT;
 
-	if (perf_event_overflow(event, 1, &data, &regs))
+	if (perf_event_overflow(event, 1, data, &regs))
 		intel_pmu_disable_event(event);
 
 out:
 	intel_pmu_pebs_enable_all();
 }
 
-static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
+static void intel_pmu_drain_pebs_nhm(struct perf_sample_data *data, struct pt_regs *iregs)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct pebs_record_nhm *at, *top;
-	struct perf_sample_data data;
 	struct perf_event *event = NULL;
 	struct perf_raw_record raw;
 	struct pt_regs regs;
@@ -575,13 +572,12 @@ static void intel_pmu_drain_pebs_nhm(str
 		if (!intel_pmu_save_and_restart(event))
 			continue;
 
-		perf_sample_data_init(&data, 0);
-		data.period = event->hw.last_period;
+		data->period = event->hw.last_period;
 
 		if (event->attr.sample_type & PERF_SAMPLE_RAW) {
 			raw.size = x86_pmu.pebs_record_size;
 			raw.data = at;
-			data.raw = &raw;
+			data->raw = &raw;
 		}
 
 		/*
@@ -597,7 +593,7 @@ static void intel_pmu_drain_pebs_nhm(str
 		else
 			regs.flags &= ~PERF_EFLAGS_EXACT;
 
-		if (perf_event_overflow(event, 1, &data, &regs))
+		if (perf_event_overflow(event, 1, data, &regs))
 			intel_pmu_disable_event(event);
 	}
 out:
Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -209,7 +209,8 @@ struct x86_pmu {
 	 */
 	int		bts, pebs;
 	int		pebs_record_size;
-	void		(*drain_pebs)(struct pt_regs *regs);
+	void		(*drain_pebs)(struct perf_sample_data *data,
+				      struct pt_regs *regs);
 	struct event_constraint *pebs_constraints;
 
 	/*
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel_lbr.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -178,7 +178,7 @@ static void intel_pmu_lbr_read_64(struct
 	cpuc->lbr_stack.nr = i;
 }
 
-static void intel_pmu_lbr_read(void)
+static void intel_pmu_lbr_read(struct perf_sample_data *data)
 {
 	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 
@@ -189,6 +189,8 @@ static void intel_pmu_lbr_read(void)
 		intel_pmu_lbr_read_32(cpuc);
 	else
 		intel_pmu_lbr_read_64(cpuc);
+
+	data->branches = &cpuc->lbr_stack;
 }
 
 static void intel_pmu_lbr_init_core(void)

--