Re: [PATCH 2/6] perf, x86: Add Haswell specific transaction flagreporting v4

From: Peter Zijlstra
Date: Mon Sep 16 2013 - 07:22:07 EST


On Fri, Sep 13, 2013 at 11:08:32AM -0700, Andi Kleen wrote:
> @@ -893,6 +895,16 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
> (x86_pmu.intel_cap.pebs_format >= 2))
> data.weight = intel_hsw_weight(pebs);
>
> + if ((event->attr.sample_type & PERF_SAMPLE_TRANSACTION) &&
> + x86_pmu.intel_cap.pebs_format >= 2) {
> + data.transaction =
> + (pebs->tsx_tuning & PEBS_HSW_TSX_FLAGS) >> 32;
> + /* For RTM XABORTs also log the abort code from AX */
> + if ((data.transaction & PERF_SAMPLE_TXN_TRANSACTION) &&
> + (pebs->ax & 1))
> + data.transaction |= pebs->ax & 0xff000000;
> + }
> +
> if (has_branch_stack(event))
> data.br_stack = &cpuc->lbr_stack;
>

Also, since we know now have 2 format >= 2 branches we can combine them;
something like so?

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index f364c13..862e59f 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -206,6 +206,8 @@ union hsw_tsx_tuning {
u64 value;
};

+#define PEBS_HSW_TSX_FLAGS 0xff00000000
+
void init_debug_store_on_cpu(int cpu)
{
struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
@@ -880,18 +882,30 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
else
regs.flags &= ~PERF_EFLAGS_EXACT;

- if ((event->attr.sample_type & PERF_SAMPLE_ADDR) &&
- x86_pmu.intel_cap.pebs_format >= 1)
+ if (has_branch_stack(event))
+ data.br_stack = &cpuc->lbr_stack;
+
+ if (x86_pmu.intel_cap.pebs_format < 1)
+ goto done;
+
+ if (event->attr.sample_type & PERF_SAMPLE_ADDR)
data.addr = pebs->dla;

+ if (x86_pmu.intel_cap.pebs_format < 2)
+ goto done;
+
/* Only set the TSX weight when no memory weight was requested. */
- if ((event->attr.sample_type & PERF_SAMPLE_WEIGHT) && !fll &&
- (x86_pmu.intel_cap.pebs_format >= 2))
+ if ((event->attr.sample_type & PERF_SAMPLE_WEIGHT) && !fll)
data.weight = intel_hsw_weight(pebs);

- if (has_branch_stack(event))
- data.br_stack = &cpuc->lbr_stack;
+ if ((event->attr.sample_type & PERF_SAMPLE_TRANSACTION)) {
+ data.txn = (pebs->tsx_tuning & PEBS_HSW_TSX_FLAGS) >> 32;
+ /* For RTM XABORTs also log the abort code from AX */
+ if ((data.txn & PERF_SAMPLE_TXN_TRANSACTION) && (pebs->ax & 1))
+ data.txn |= pebs->ax & 0xff000000;
+ }

+done:
if (perf_event_overflow(event, &data, &regs))
x86_pmu_stop(event, 0);
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/