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

[Peter Zijlstra <peterz@infradead.org>]

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);
 }