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perf/x86/intel: Fix CMT PEBS load/store direction for latency events, to fix sample classification

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The same bug exists on Crestmont as on Gracemont:
intel_cmt_pebs_event_constraints[] applies LAT_CONSTRAINT constraints to
MEM_UOPS_RETIRED.{LOAD,STORE}_LATENCY, but does not set explicit
LOAD/STORE flags for those events.

The PEBS latency path (pebs_latency_data(), via cmt_latency_data) uses
the event flags to determine memory operation direction. Without an
explicit STORE flag, samples from MEM_UOPS_RETIRED.STORE_LATENCY can be
misclassified as LOADs.

Set explicit LOAD/STORE flags in intel_cmt_pebs_event_constraints[] for:

- MEM_UOPS_RETIRED.LOAD_LATENCY
- MEM_UOPS_RETIRED.STORE_LATENCY

This fixes incorrect STORE sample classification.

Fixes: e99fb45436 ("perf/x86/intel: Update event constraints and cache_extra_regsfor MTL")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org> # v7.2+
Link: https://patch.msgid.link/20260917015234.981153-3-dapeng1.mi@linux.intel.com
This commit is contained in:
Dapeng Mi 2026-09-17 09:52:24 +08:00 committed by Ingo Molnar
parent 89dc568e8c
commit e961d6db42
1 changed files with 2 additions and 2 deletions
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4
arch/x86/events/intel/ds.c
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@ -1308,8 +1308,8 @@ struct event_constraint intel_grt_pebs_event_constraints[] = {
struct event_constraint intel_cmt_pebs_event_constraints[] = {
/* Allow all events as PEBS with no flags */
INTEL_HYBRID_LAT_CONSTRAINT(0x5d0, 0x3),
INTEL_HYBRID_LAT_CONSTRAINT(0x6d0, 0xff),
INTEL_HYBRID_LDLAT_CONSTRAINT(0x5d0, 0x3),
INTEL_HYBRID_STLAT_CONSTRAINT(0x6d0, 0xff),
EVENT_CONSTRAINT_END
};