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SubjectRe: [PATCH 4/5] x86, perf: Add conditional branch filtering support
From
On Wed, May 22, 2013 at 8:22 AM, Anshuman Khandual
<khandual@linux.vnet.ibm.com> wrote:
> From: Peter Zijlstra <a.p.zijlstra@chello.nl>
>
> 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.
>
Reviewed-by: Stephane Eranian <eranian@google.com>

> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
> ---
> arch/x86/kernel/cpu/perf_event_intel_lbr.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> index d978353..a0d6387 100644
> --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
> @@ -337,6 +337,10 @@ static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event)
>
> if (br_type & PERF_SAMPLE_BRANCH_IND_CALL)
> mask |= X86_BR_IND_CALL;
> +
> + 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
> @@ -626,6 +630,7 @@ 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] = {
> @@ -637,6 +642,7 @@ 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
>


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