[V5 0/4] perf: New conditional branch filter

[V5 0/4] perf: New conditional branch filter

[Anshuman Khandual]

Hello Arnaldo,

	I had posted the V5 version of PowerPC SW branch filter enablement
patchset last month. Please find the patchset here at

	https://lkml.org/lkml/2014/2/5/79

These following patches (2,4,5,6 patches from the original V5 version patchset)
are the ones which change code in the generic kernel, perf tool and X86 perf.
Basically this patchset adds one more branch filter for "conditional" branches.
In X86 code, this new filter has been implemented with the help of availble SW
filter X86_BR_JCC and LBR_JCC. We had some discussions in this regard before.
Please review these changes and if it's okay, please merge them. Other patches
in the series are powerpc specific and are being reviewed by Benjamin Herrenschmidt
and Michael Ellerman. Let me know if you need more information.

[1] https://lkml.org/lkml/2013/5/22/51
[2] https://lkml.org/lkml/2013/8/30/10
[3] https://lkml.org/lkml/2013/10/16/75
[4] https://lkml.org/lkml/2013/12/4/168
[5] https://lkml.org/lkml/2014/2/5/79

c: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>

Anshuman Khandual (4):
  perf: Add PERF_SAMPLE_BRANCH_COND
  perf, tool: Conditional branch filter 'cond' added to perf record
  x86, perf: Add conditional branch filtering support
  perf, documentation: Description for conditional branch filter

 arch/x86/kernel/cpu/perf_event_intel_lbr.c | 5 +++++
 include/uapi/linux/perf_event.h            | 3 ++-
 tools/perf/Documentation/perf-record.txt   | 3 ++-
 tools/perf/builtin-record.c                | 1 +
 4 files changed, 10 insertions(+), 2 deletions(-)

-- 
1.7.11.7

[V5 1/4] perf: Add PERF_SAMPLE_BRANCH_COND

[Anshuman Khandual]

This patch introduces new branch filter PERF_SAMPLE_BRANCH_COND which
will extend the existing perf ABI. Various architectures can provide
this functionality with either with HW filtering support (if present)
or with SW filtering of captured branch instructions.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
---
 include/uapi/linux/perf_event.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 853bc1c..696f69b4 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -163,8 +163,9 @@ enum perf_branch_sample_type {
 	PERF_SAMPLE_BRANCH_ABORT_TX	= 1U << 7, /* transaction aborts */
 	PERF_SAMPLE_BRANCH_IN_TX	= 1U << 8, /* in transaction */
 	PERF_SAMPLE_BRANCH_NO_TX	= 1U << 9, /* not in transaction */
+	PERF_SAMPLE_BRANCH_COND		= 1U << 10, /* conditional branches */
 
-	PERF_SAMPLE_BRANCH_MAX		= 1U << 10, /* non-ABI */
+	PERF_SAMPLE_BRANCH_MAX		= 1U << 11, /* non-ABI */
 };
 
 #define PERF_SAMPLE_BRANCH_PLM_ALL \
-- 
1.7.11.7

[V5 2/4] perf, tool: Conditional branch filter 'cond' added to perf record

[Anshuman Khandual]

Adding perf record support for new branch stack filter criteria
PERF_SAMPLE_BRANCH_COND.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
---
 tools/perf/builtin-record.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3c394bf..eb74bcd 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -589,6 +589,7 @@ static const struct branch_mode branch_modes[] = {
 	BRANCH_OPT("abort_tx", PERF_SAMPLE_BRANCH_ABORT_TX),
 	BRANCH_OPT("in_tx", PERF_SAMPLE_BRANCH_IN_TX),
 	BRANCH_OPT("no_tx", PERF_SAMPLE_BRANCH_NO_TX),
+	BRANCH_OPT("cond", PERF_SAMPLE_BRANCH_COND),
 	BRANCH_END
 };
 
-- 
1.7.11.7

[V5 3/4] x86, perf: Add conditional branch filtering support

[Anshuman Khandual]

This patch adds conditional branch filtering support,
enabling it for PERF_SAMPLE_BRANCH_COND in perf branch
stack sampling framework by utilizing an available
software filter X86_BR_JCC.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
---
 arch/x86/kernel/cpu/perf_event_intel_lbr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index d82d155..9dd2459 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -384,6 +384,9 @@ static void intel_pmu_setup_sw_lbr_filter(struct perf_event *event)
 	if (br_type & PERF_SAMPLE_BRANCH_NO_TX)
 		mask |= X86_BR_NO_TX;
 
+	if (br_type & PERF_SAMPLE_BRANCH_COND)
+		mask |= X86_BR_JCC;
+
 	/*
 	 * stash actual user request into reg, it may
 	 * be used by fixup code for some CPU
@@ -678,6 +681,7 @@ static const int nhm_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
 	 * NHM/WSM erratum: must include IND_JMP to capture IND_CALL
 	 */
 	[PERF_SAMPLE_BRANCH_IND_CALL] = LBR_IND_CALL | LBR_IND_JMP,
+	[PERF_SAMPLE_BRANCH_COND]     = LBR_JCC,
 };
 
 static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
@@ -689,6 +693,7 @@ static const int snb_lbr_sel_map[PERF_SAMPLE_BRANCH_MAX] = {
 	[PERF_SAMPLE_BRANCH_ANY_CALL]	= LBR_REL_CALL | LBR_IND_CALL
 					| LBR_FAR,
 	[PERF_SAMPLE_BRANCH_IND_CALL]	= LBR_IND_CALL,
+	[PERF_SAMPLE_BRANCH_COND]       = LBR_JCC,
 };
 
 /* core */
-- 
1.7.11.7

[V5 4/4] perf, documentation: Description for conditional branch filter

[Anshuman Khandual]

Adding documentation support for conditional branch filter.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Stephane Eranian <eranian@google.com>
---
 tools/perf/Documentation/perf-record.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index c71b0f3..d460049 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -184,9 +184,10 @@ following filters are defined:
 	- in_tx: only when the target is in a hardware transaction
 	- no_tx: only when the target is not in a hardware transaction
 	- abort_tx: only when the target is a hardware transaction abort
+	- cond: conditional branches
 
 +
-The option requires at least one branch type among any, any_call, any_ret, ind_call.
+The option requires at least one branch type among any, any_call, any_ret, ind_call, cond.
 The privilege levels may be omitted, in which case, the privilege levels of the associated
 event are applied to the branch filter. Both kernel (k) and hypervisor (hv) privilege
 levels are subject to permissions.  When sampling on multiple events, branch stack sampling
-- 
1.7.11.7

Re: [V5 0/4] perf: New conditional branch filter

[Anshuman Khandual]

On 03/07/2014 02:36 PM, Anshuman Khandual wrote:
> Hello Arnaldo,
> 
> 	I had posted the V5 version of PowerPC SW branch filter enablement
> patchset last month. Please find the patchset here at
> 
> 	https://lkml.org/lkml/2014/2/5/79
> 
> These following patches (2,4,5,6 patches from the original V5 version patchset)
> are the ones which change code in the generic kernel, perf tool and X86 perf.
> Basically this patchset adds one more branch filter for "conditional" branches.
> In X86 code, this new filter has been implemented with the help of availble SW
> filter X86_BR_JCC and LBR_JCC. We had some discussions in this regard before.
> Please review these changes and if it's okay, please merge them. Other patches
> in the series are powerpc specific and are being reviewed by Benjamin Herrenschmidt
> and Michael Ellerman. Let me know if you need more information.
> 
> [1] https://lkml.org/lkml/2013/5/22/51
> [2] https://lkml.org/lkml/2013/8/30/10
> [3] https://lkml.org/lkml/2013/10/16/75
> [4] https://lkml.org/lkml/2013/12/4/168
> [5] https://lkml.org/lkml/2014/2/5/79

Hey Arnaldo,

Do you have any comments or suggestions on this ? Have not received any
response on these proposed patch series yet. Thank you.

Re: [V5 0/4] perf: New conditional branch filter

[Andi Kleen]

> Hey Arnaldo,
> 
> Do you have any comments or suggestions on this ? Have not received any
> response on these proposed patch series yet. Thank you.

I read it earlier and it looks good to me.

-Andi

Re: [V5 0/4] perf: New conditional branch filter

[Anshuman Khandual]

On 03/25/2014 09:46 PM, Andi Kleen wrote:
>> Hey Arnaldo,
>>
>> Do you have any comments or suggestions on this ? Have not received any
>> response on these proposed patch series yet. Thank you.
> 
> I read it earlier and it looks good to me.

Hey Andi,

Can I add your "Reviewed-by" or "Acked-by" to all these four patches ?

Re: [V5 0/4] perf: New conditional branch filter

[Andi Kleen]

On Mon, Apr 07, 2014 at 01:50:26PM +0530, Anshuman Khandual wrote:
> On 03/25/2014 09:46 PM, Andi Kleen wrote:
> >> Hey Arnaldo,
> >>
> >> Do you have any comments or suggestions on this ? Have not received any
> >> response on these proposed patch series yet. Thank you.
> > 
> > I read it earlier and it looks good to me.
> 
> Hey Andi,
> 
> Can I add your "Reviewed-by" or "Acked-by" to all these four patches ?

Ok for me.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only

Re: [V5 0/4] perf: New conditional branch filter

[Andi Kleen]

> Do you have any comments or suggestions on this ? Have not received any
> response on these proposed patch series yet. Thank you.

Also BTW I'm also at least three patchkits behind on perf tools merges,
some of them several weeks old.

Perhaps we need a staging tree somewhere to collect all the patches
until they can actually get processed.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only