[tip:perf/core] perf/x86: Add conditional branch filtering support

From: tip-bot for Anshuman Khandual
Date: Thu Jun 05 2014 - 10:40:53 EST


Commit-ID: 37548914fbfcd56e1955a9b7e55dc3b84a3e9e25
Gitweb: http://git.kernel.org/tip/37548914fbfcd56e1955a9b7e55dc3b84a3e9e25
Author: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
AuthorDate: Thu, 22 May 2014 12:50:09 +0530
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 5 Jun 2014 12:30:23 +0200

perf/x86: Add conditional branch filtering support

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@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Stephane Eranian <eranian@xxxxxxxxxx>
Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: mpe@xxxxxxxxxxxxxx
Cc: benh@xxxxxxxxxxxxxxxxxxx
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1400743210-32289-3-git-send-email-khandual@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
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 */
--
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