[patch 0/4] perf,p4 series for -tip

[patch 0/4] perf,p4 series for -tip

[Cyrill Gorcunov]

Hi,

please review and test if possible. Any complains
are quite welcome! Thanks!

Cyrill

[patch 1/4] x86,perf: P4 PMU -- configurate predefined events

[Cyrill Gorcunov]

[-- Attachment #1: x86-perf-p4-repir-raw --]
[-- Type: text/plain, Size: 2054 bytes --]

If an event is not RAW we should exit p4_hw_config
early but call x86_setup_perfctr as well.

CC: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Robert Richter <robert.richter@amd.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---

Robert, if only I'm not missing something this is
a side effect of commit 9d0fcba67e47ff398a6fa86476d4884d472dc98a,
wonders why don't we hit it earlier. Am I wrong?

 arch/x86/kernel/cpu/perf_event_p4.c |   29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
=====================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
@@ -439,21 +439,20 @@ static int p4_hw_config(struct perf_even
 	if (p4_ht_active() && p4_ht_thread(cpu))
 		event->hw.config = p4_set_ht_bit(event->hw.config);
 
-	if (event->attr.type != PERF_TYPE_RAW)
-		return 0;
-
-	/*
-	 * We don't control raw events so it's up to the caller
-	 * to pass sane values (and we don't count the thread number
-	 * on HT machine but allow HT-compatible specifics to be
-	 * passed on)
-	 *
-	 * XXX: HT wide things should check perf_paranoid_cpu() &&
-	 *      CAP_SYS_ADMIN
-	 */
-	event->hw.config |= event->attr.config &
-		(p4_config_pack_escr(P4_ESCR_MASK_HT) |
-		 p4_config_pack_cccr(P4_CCCR_MASK_HT));
+	if (event->attr.type == PERF_TYPE_RAW) {
+		/*
+		 * We don't control raw events so it's up to the caller
+		 * to pass sane values (and we don't count the thread number
+		 * on HT machine but allow HT-compatible specifics to be
+		 * passed on)
+		 *
+		 * XXX: HT wide things should check perf_paranoid_cpu() &&
+		 *      CAP_SYS_ADMIN
+		 */
+		event->hw.config |= event->attr.config &
+			(p4_config_pack_escr(P4_ESCR_MASK_HT) |
+			 p4_config_pack_cccr(P4_CCCR_MASK_HT));
+	}
 
 	return x86_setup_perfctr(event);
 }

[patch 2/4] x86,perf: P4 PMU -- protect sensible procedures from preemption

[Cyrill Gorcunov]

[-- Attachment #1: x86-perf-p4-getcpu --]
[-- Type: text/plain, Size: 2525 bytes --]

Steven reported
|
| I'm getting:
|
| Pid: 3477, comm: perf Not tainted 2.6.34-rc6 #2727
| Call Trace:
|  [<ffffffff811c7565>] debug_smp_processor_id+0xd5/0xf0
|  [<ffffffff81019874>] p4_hw_config+0x2b/0x15c
|  [<ffffffff8107acbc>] ? trace_hardirqs_on_caller+0x12b/0x14f
|  [<ffffffff81019143>] hw_perf_event_init+0x468/0x7be
|  [<ffffffff810782fd>] ? debug_mutex_init+0x31/0x3c
|  [<ffffffff810c68b2>] T.850+0x273/0x42e
|  [<ffffffff810c6cab>] sys_perf_event_open+0x23e/0x3f1
|  [<ffffffff81009e6a>] ? sysret_check+0x2e/0x69
|  [<ffffffff81009e32>] system_call_fastpath+0x16/0x1b
|
| When running perf record in latest tip/perf/core
|

Due to the fact that p4 counters are shared between HT threads
we synthetically divide the whole set of counters into two
non-intersected subsets. And while we're "borrowing" counters
from these subsets we should not be preempted (well, strictly
speaking in p4_hw_config we just pre-set reference to the
subset which allow to save some cycles in schedule routine
if it happens on the same cpu). So use get_cpu/put_cpu pair.

Also p4_pmu_schedule_events should use smp_processor_id rather
than raw_ version. This allow us to catch up preemption issue
(if there will ever be).

Reported-by: Steven Rostedt <rostedt@goodmis.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---
Note: I've removed Steven's Tested-by tag, since due to
commit 9d0fcba67e47ff398a6fa86476d4884d472dc98a the former
patch Steven were testing is not applicable anymore.

 arch/x86/kernel/cpu/perf_event_p4.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
=====================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
@@ -421,7 +421,8 @@ static u64 p4_pmu_event_map(int hw_event
 
 static int p4_hw_config(struct perf_event *event)
 {
-	int cpu = raw_smp_processor_id();
+	int cpu = get_cpu();
+	int rc = 0;
 	u32 escr, cccr;
 
 	/*
@@ -454,7 +455,10 @@ static int p4_hw_config(struct perf_even
 			 p4_config_pack_cccr(P4_CCCR_MASK_HT));
 	}
 
-	return x86_setup_perfctr(event);
+	rc = x86_setup_perfctr(event);
+	put_cpu();
+
+	return rc;
 }
 
 static inline void p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc)

[patch 3/4] x86,perf: P4 PMU -- Get rid of redundant check for array index

[Cyrill Gorcunov]

[-- Attachment #1: x86-perf-p4-redundant-check --]
[-- Type: text/plain, Size: 984 bytes --]

The caller already has done such a check.
And it was wrong anyway, it had to be '>=' rather then '>'

CC: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---
 arch/x86/kernel/cpu/perf_event_p4.c |    5 -----
 1 file changed, 5 deletions(-)

Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
=====================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
@@ -406,11 +406,6 @@ static u64 p4_pmu_event_map(int hw_event
 	unsigned int esel;
 	u64 config;
 
-	if (hw_event > ARRAY_SIZE(p4_general_events)) {
-		printk_once(KERN_ERR "P4 PMU: Bad index: %i\n", hw_event);
-		return 0;
-	}
-
 	config = p4_general_events[hw_event];
 	bind = p4_config_get_bind(config);
 	esel = P4_OPCODE_ESEL(bind->opcode);

[patch 4/4] x86,perf: P4 PMU -- check for proper event index in RAW events

[Cyrill Gorcunov]

[-- Attachment #1: x86-perf-p4-raw-index --]
[-- Type: text/plain, Size: 1416 bytes --]

RAW events are special and we should be ready for user passing
insane event index.

CC: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---
 arch/x86/kernel/cpu/perf_event_p4.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
=====================================================================
--- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
+++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
@@ -418,6 +418,7 @@ static int p4_hw_config(struct perf_even
 {
 	int cpu = get_cpu();
 	int rc = 0;
+	unsigned int evnt;
 	u32 escr, cccr;
 
 	/*
@@ -436,6 +437,14 @@ static int p4_hw_config(struct perf_even
 		event->hw.config = p4_set_ht_bit(event->hw.config);
 
 	if (event->attr.type == PERF_TYPE_RAW) {
+
+		/* user data may have out-of-bound event index */
+		evnt = p4_config_unpack_event(event->attr.config);
+		if (evnt >= ARRAY_SIZE(p4_event_bind_map)) {
+			rc = -EINVAL;
+			goto out;
+		}
+
 		/*
 		 * We don't control raw events so it's up to the caller
 		 * to pass sane values (and we don't count the thread number
@@ -451,8 +460,8 @@ static int p4_hw_config(struct perf_even
 	}
 
 	rc = x86_setup_perfctr(event);
+out:
 	put_cpu();
-
 	return rc;
 }
 

Re: [patch 1/4] x86,perf: P4 PMU -- configurate predefined events

[Cyrill Gorcunov]

On Saturday, May 8, 2010, Cyrill Gorcunov <gorcunov@openvz.org> wrote:
> If an event is not RAW we should exit p4_hw_config
> early but call x86_setup_perfctr as well.
>

Actually i meant "should not"

> CC: Peter Zijlstra <peterz@infradead.org>
> CC: Ingo Molnar <mingo@elte.hu>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Lin Ming <ming.m.lin@intel.com>
> CC: Robert Richter <robert.richter@amd.com>
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> ---
>
> Robert, if only I'm not missing something this is
> a side effect of commit 9d0fcba67e47ff398a6fa86476d4884d472dc98a,
> wonders why don't we hit it earlier. Am I wrong?
>
>  arch/x86/kernel/cpu/perf_event_p4.c |   29 ++++++++++++++---------------
>  1 file changed, 14 insertions(+), 15 deletions(-)
>
> Index: linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
> =====================================================================
> --- linux-2.6.git.orig/arch/x86/kernel/cpu/perf_event_p4.c
> +++ linux-2.6.git/arch/x86/kernel/cpu/perf_event_p4.c
> @@ -439,21 +439,20 @@ static int p4_hw_config(struct perf_even
>         if (p4_ht_active() && p4_ht_thread(cpu))
>                 event->hw.config = p4_set_ht_bit(event->hw.config);
>
> -       if (event->attr.type != PERF_TYPE_RAW)
> -               return 0;
> -
> -       /*
> -        * We don't control raw events so it's up to the caller
> -        * to pass sane values (and we don't count the thread number
> -        * on HT machine but allow HT-compatible specifics to be
> -        * passed on)
> -        *
> -        * XXX: HT wide things should check perf_paranoid_cpu() &&
> -        *      CAP_SYS_ADMIN
> -        */
> -       event->hw.config |= event->attr.config &
> -               (p4_config_pack_escr(P4_ESCR_MASK_HT) |
> -                p4_config_pack_cccr(P4_CCCR_MASK_HT));
> +       if (event->attr.type == PERF_TYPE_RAW) {
> +               /*
> +                * We don't control raw events so it's up to the caller
> +                * to pass sane values (and we don't count the thread number
> +                * on HT machine but allow HT-compatible specifics to be
> +                * passed on)
> +                *
> +                * XXX: HT wide things should check perf_paranoid_cpu() &&
> +                *      CAP_SYS_ADMIN
> +                */
> +               event->hw.config |= event->attr.config &
> +                       (p4_config_pack_escr(P4_ESCR_MASK_HT) |
> +                        p4_config_pack_cccr(P4_CCCR_MASK_HT));
> +       }
>
>         return x86_setup_perfctr(event);
>  }
>
>

[tip:perf/core] x86, perf: P4 PMU -- protect sensible procedures from preemption

[tip-bot for Cyrill Gorcunov]

Commit-ID:  137351e0feeb9f25d99488ee1afc1c79f5499a9a
Gitweb:     http://git.kernel.org/tip/137351e0feeb9f25d99488ee1afc1c79f5499a9a
Author:     Cyrill Gorcunov <gorcunov@openvz.org>
AuthorDate: Sat, 8 May 2010 15:25:52 +0400
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 8 May 2010 14:17:53 +0200

x86, perf: P4 PMU -- protect sensible procedures from preemption

Steven reported:

|
| I'm getting:
|
| Pid: 3477, comm: perf Not tainted 2.6.34-rc6 #2727
| Call Trace:
|  [<ffffffff811c7565>] debug_smp_processor_id+0xd5/0xf0
|  [<ffffffff81019874>] p4_hw_config+0x2b/0x15c
|  [<ffffffff8107acbc>] ? trace_hardirqs_on_caller+0x12b/0x14f
|  [<ffffffff81019143>] hw_perf_event_init+0x468/0x7be
|  [<ffffffff810782fd>] ? debug_mutex_init+0x31/0x3c
|  [<ffffffff810c68b2>] T.850+0x273/0x42e
|  [<ffffffff810c6cab>] sys_perf_event_open+0x23e/0x3f1
|  [<ffffffff81009e6a>] ? sysret_check+0x2e/0x69
|  [<ffffffff81009e32>] system_call_fastpath+0x16/0x1b
|
| When running perf record in latest tip/perf/core
|

Due to the fact that p4 counters are shared between HT threads
we synthetically divide the whole set of counters into two
non-intersected subsets. And while we're "borrowing" counters
from these subsets we should not be preempted (well, strictly
speaking in p4_hw_config we just pre-set reference to the
subset which allow to save some cycles in schedule routine
if it happens on the same cpu). So use get_cpu/put_cpu pair.

Also p4_pmu_schedule_events should use smp_processor_id rather
than raw_ version. This allow us to catch up preemption issue
(if there will ever be).

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100508112716.963478928@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event_p4.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index b1f532d..ca40180 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -421,7 +421,8 @@ static u64 p4_pmu_event_map(int hw_event)
 
 static int p4_hw_config(struct perf_event *event)
 {
-	int cpu = raw_smp_processor_id();
+	int cpu = get_cpu();
+	int rc = 0;
 	u32 escr, cccr;
 
 	/*
@@ -454,7 +455,10 @@ static int p4_hw_config(struct perf_event *event)
 			 p4_config_pack_cccr(P4_CCCR_MASK_HT));
 	}
 
-	return x86_setup_perfctr(event);
+	rc = x86_setup_perfctr(event);
+	put_cpu();
+
+	return rc;
 }
 
 static inline void p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc)

[tip:perf/core] x86, perf: P4 PMU -- Get rid of redundant check for array index

[tip-bot for Cyrill Gorcunov]

Commit-ID:  3f51b7119d052827dbb0e40c966acdf2bdc6f47f
Gitweb:     http://git.kernel.org/tip/3f51b7119d052827dbb0e40c966acdf2bdc6f47f
Author:     Cyrill Gorcunov <gorcunov@openvz.org>
AuthorDate: Sat, 8 May 2010 15:25:53 +0400
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 8 May 2010 14:17:53 +0200

x86, perf: P4 PMU -- Get rid of redundant check for array index

The caller already has done such a check.
And it was wrong anyway, it had to be '>=' rather than '>'

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100508112717.130386882@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event_p4.c |    5 -----
 1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index ca40180..b8c2d37 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -406,11 +406,6 @@ static u64 p4_pmu_event_map(int hw_event)
 	unsigned int esel;
 	u64 config;
 
-	if (hw_event > ARRAY_SIZE(p4_general_events)) {
-		printk_once(KERN_ERR "P4 PMU: Bad index: %i\n", hw_event);
-		return 0;
-	}
-
 	config = p4_general_events[hw_event];
 	bind = p4_config_get_bind(config);
 	esel = P4_OPCODE_ESEL(bind->opcode);

[tip:perf/core] x86, perf: P4 PMU -- check for proper event index in RAW events

[tip-bot for Cyrill Gorcunov]

Commit-ID:  c7993165ef0c1d636ca05f4787739f8414584e6d
Gitweb:     http://git.kernel.org/tip/c7993165ef0c1d636ca05f4787739f8414584e6d
Author:     Cyrill Gorcunov <gorcunov@openvz.org>
AuthorDate: Sat, 8 May 2010 15:25:54 +0400
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Sat, 8 May 2010 14:17:53 +0200

x86, perf: P4 PMU -- check for proper event index in RAW events

RAW events are special and we should be ready for user passing
in insane event index values.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
LKML-Reference: <20100508112717.315897547@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event_p4.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index b8c2d37..a603930 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -418,6 +418,7 @@ static int p4_hw_config(struct perf_event *event)
 {
 	int cpu = get_cpu();
 	int rc = 0;
+	unsigned int evnt;
 	u32 escr, cccr;
 
 	/*
@@ -436,6 +437,14 @@ static int p4_hw_config(struct perf_event *event)
 		event->hw.config = p4_set_ht_bit(event->hw.config);
 
 	if (event->attr.type == PERF_TYPE_RAW) {
+
+		/* user data may have out-of-bound event index */
+		evnt = p4_config_unpack_event(event->attr.config);
+		if (evnt >= ARRAY_SIZE(p4_event_bind_map)) {
+			rc = -EINVAL;
+			goto out;
+		}
+
 		/*
 		 * We don't control raw events so it's up to the caller
 		 * to pass sane values (and we don't count the thread number
@@ -451,8 +460,8 @@ static int p4_hw_config(struct perf_event *event)
 	}
 
 	rc = x86_setup_perfctr(event);
+out:
 	put_cpu();
-
 	return rc;
 }
 

Re: [patch 1/4] x86,perf: P4 PMU -- configurate predefined events

[Robert Richter]

On 08.05.10 07:25:51, Cyrill Gorcunov wrote:
> If an event is not RAW we should exit p4_hw_config
> early but call x86_setup_perfctr as well.
> 
> CC: Peter Zijlstra <peterz@infradead.org>
> CC: Ingo Molnar <mingo@elte.hu>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Lin Ming <ming.m.lin@intel.com>
> CC: Robert Richter <robert.richter@amd.com>
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> ---
> 
> Robert, if only I'm not missing something this is
> a side effect of commit 9d0fcba67e47ff398a6fa86476d4884d472dc98a,
> wonders why don't we hit it earlier. Am I wrong?

Yes, that's true, the function had have two exit points. Thanks for
the fix.

-Robert

-- 
Advanced Micro Devices, Inc.
Operating System Research Center
email: robert.richter@amd.com