Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Thu, 15 May 2014 17:56:44 +0200 | From | Stephane Eranian <> | Subject | [PATCH v2]: fix Haswell precise store data source encoding |
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This patch fixes a bug in precise_store_data_hsw() whereby it would set the data source memory level to the wrong value.
As per the the SDM Vol 3b Table 18-41 (Layout of Data Linear Address Information in PEBS Record), when status bit 0 is set this is a L1 hit, otherwise this is a L1 miss.
This patch encodes the memory level according to the specification.
In V2, we added the filtering on the store events. Only the following events produce L1 information: * MEM_UOPS_RETIRED.STLB_MISS_STORES * MEM_UOPS_RETIRED.LOCK_STORES * MEM_UOPS_RETIRED.SPLIT_STORES * MEM_UOPS_RETIRED.ALL_STORES
Signed-off-by: Stephane Eranian <eranian@google.com>
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c index ae96cfa..980970c 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_ds.c +++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c @@ -108,15 +108,31 @@ static u64 precise_store_data(u64 status) return val; } -static u64 precise_store_data_hsw(u64 status) +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_STORE; dse.mem_lvl = PERF_MEM_LVL_NA; + + /* + * L1 info only valid for following events: + * + * MEM_UOPS_RETIRED.STLB_MISS_STORES + * MEM_UOPS_RETIRED.LOCK_STORES + * MEM_UOPS_RETIRED.SPLIT_STORES + * MEM_UOPS_RETIRED.ALL_STORES + */ + if (cfg != 0x12d0 && cfg != 0x22d0 && cfg != 0x42d0 && cfg != 0x82d0) + return dse.mem_lvl; + if (status & 1) - dse.mem_lvl = PERF_MEM_LVL_L1; + dse.mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_HIT; + else + dse.mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_MISS; + /* Nothing else supported. Sorry. */ return dse.val; } @@ -887,7 +903,7 @@ static void __intel_pmu_pebs_event(struct perf_event *event, data.data_src.val = load_latency_data(pebs->dse); else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST_HSW) data.data_src.val = - precise_store_data_hsw(pebs->dse); + precise_store_data_hsw(event, pebs->dse); else data.data_src.val = precise_store_data(pebs->dse); }
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