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

From: Stephane Eranian
Date: Mon Aug 11 2014 - 15:26:49 EST


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@xxxxxxxxxx>
Date: Thu May 15 17:56:44 2014 +0200

fix Haswell precise store data source encoding

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
---
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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