linux-kernel - [PATCH v2 3/4] perf/x86: fix data source encoding issues for load latency/precise store

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Date:	Mon, 11 Aug 2014 21:27:12 +0200
From:	Stephane Eranian <eranian@...gle.com>
To:	linux-kernel@...r.kernel.org
Cc:	peterz@...radead.org, mingo@...e.hu, ak@...ux.intel.com
Subject: [PATCH v2 3/4] perf/x86: fix data source encoding issues for load latency/precise store

This patch fixes issues introuduce by Andi's previous patch 'Revamp PEBS'
series.

This patch fixes the following:
 - precise_store_data_hsw() encode the mem op type whenever we can
 - precise_store_data_hsw set the default data source correctly

 - 0 is not a valid init value for data source. Define PERF_MEM_NA as the
   default value

This bug was actually introduced by

    commit 722e76e60f2775c21b087ff12c5e678cf0ebcaaf
    Author: Stephane Eranian <eranian@...gle.com>
    Date:   Thu May 15 17:56:44 2014 +0200

        fix Haswell precise store data source encoding

Signed-off-by: Stephane Eranian <eranian@...gle.com>
---
 arch/x86/kernel/cpu/perf_event_intel_ds.c |   11 +++++++----
 include/linux/perf_event.h                |    9 ++++++++-
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index a9b60f3..67919ce 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -113,9 +113,12 @@ static u64 precise_store_data_hsw(struct perf_event *event, u64 status)
 	union perf_mem_data_src dse;
 	u64 cfg = event->hw.config & INTEL_ARCH_EVENT_MASK;
 
-	dse.val = 0;
-	dse.mem_op = PERF_MEM_OP_NA;
-	dse.mem_lvl = PERF_MEM_LVL_NA;
+	dse.val = PERF_MEM_NA;
+
+	if (event->hw.flags & PERF_X86_EVENT_PEBS_ST_HSW)
+		dse.mem_op = PERF_MEM_OP_STORE;
+	else if (event->hw.flags & PERF_X86_EVENT_PEBS_LD_HSW)
+		dse.mem_op = PERF_MEM_OP_LOAD;
 
 	/*
 	 * L1 info only valid for following events:
@@ -126,7 +129,7 @@ static u64 precise_store_data_hsw(struct perf_event *event, u64 status)
 	 * MEM_UOPS_RETIRED.ALL_STORES
 	 */
 	if (cfg != 0x12d0 && cfg != 0x22d0 && cfg != 0x42d0 && cfg != 0x82d0)
-		return dse.mem_lvl;
+		return dse.val;
 
 	if (status & 1)
 		dse.mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_HIT;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 707617a..8b206aa 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -604,6 +604,13 @@ struct perf_sample_data {
 	u64				txn;
 };
 
+/* default value for data source */
+#define PERF_MEM_NA (PERF_MEM_S(OP, NA)   |\
+		    PERF_MEM_S(LVL, NA)   |\
+		    PERF_MEM_S(SNOOP, NA) |\
+		    PERF_MEM_S(LOCK, NA)  |\
+		    PERF_MEM_S(TLB, NA))
+
 static inline void perf_sample_data_init(struct perf_sample_data *data,
 					 u64 addr, u64 period)
 {
@@ -616,7 +623,7 @@ static inline void perf_sample_data_init(struct perf_sample_data *data,
 	data->regs_user.regs = NULL;
 	data->stack_user_size = 0;
 	data->weight = 0;
-	data->data_src.val = 0;
+	data->data_src.val = PERF_MEM_NA;
 	data->txn = 0;
 }
 
-- 
1.7.9.5

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