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perf/x86/intel: Don't extend the pseudo-encoding to GP counters

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The INST_RETIRED.PREC_DIST event (0x0100) doesn't count on SPR.
perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0

 Performance counter stats for 'CPU(s) 0':

           607,246      cpu/event=0xc0,umask=0x0/
                 0      cpu/event=0x0,umask=0x1/

The encoding for INST_RETIRED.PREC_DIST is pseudo-encoding, which
doesn't work on the generic counters. However, current perf extends its
mask to the generic counters.

The pseudo event-code for a fixed counter must be 0x00. Check and avoid
extending the mask for the fixed counter event which using the
pseudo-encoding, e.g., ref-cycles and PREC_DIST event.

With the patch,
perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0

 Performance counter stats for 'CPU(s) 0':

           583,184      cpu/event=0xc0,umask=0x0/
           583,048      cpu/event=0x0,umask=0x1/

Fixes: 2de71ee153 ("perf/x86/intel: Fix ICL/SPR INST_RETIRED.PREC_DIST encodings")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1648482543-14923-1-git-send-email-kan.liang@linux.intel.com
This commit is contained in:
Kan Liang 2022-03-28 08:49:02 -07:00 committed by Peter Zijlstra
parent e3265a4386
commit 4a263bf331
2 changed files with 10 additions and 1 deletions
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6
arch/x86/events/intel/core.c
View File

@ -5536,7 +5536,11 @@ static void intel_pmu_check_event_constraints(struct event_constraint *event_con
/* Disabled fixed counters which are not in CPUID */
c->idxmsk64 &= intel_ctrl;
if (c->idxmsk64 != INTEL_PMC_MSK_FIXED_REF_CYCLES)
/*
* Don't extend the pseudo-encoding to the
* generic counters
*/
if (!use_fixed_pseudo_encoding(c->code))
c->idxmsk64 |= (1ULL << num_counters) - 1;
}
c->idxmsk64 &=

5
arch/x86/include/asm/perf_event.h
View File

@ -241,6 +241,11 @@ struct x86_pmu_capability {
#define INTEL_PMC_IDX_FIXED_SLOTS (INTEL_PMC_IDX_FIXED + 3)
#define INTEL_PMC_MSK_FIXED_SLOTS (1ULL << INTEL_PMC_IDX_FIXED_SLOTS)
static inline bool use_fixed_pseudo_encoding(u64 code)
{
return !(code & 0xff);
}
/*
* We model BTS tracing as another fixed-mode PMC.
*