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* [PATCH] perf/x86/zhaoxin: Fix instructions error by missing fixedctr member
@ 2025-06-19  3:19 tanze
  2025-06-19 14:33 ` Liang, Kan
  2025-09-28  9:44 ` [PATCH] " tanze
  0 siblings, 2 replies; 9+ messages in thread
From: tanze @ 2025-06-19  3:19 UTC (permalink / raw)
  To: peterz, kan.liang; +Cc: linux-perf-users, linux-kernel, x86, tanze

Perf's instructions event tests on Zhaoxin CPUs may exhibit:

  $perf stat -e instructions,cycles ls -l

  ......
  Performance counter stats for 'ls -l':

                 0      instructions                     #    0.00  insn per cycle
         9,488,278      cycles

       0.004365407 seconds time elapsed

       0.003303000 seconds user
       0.001099000 seconds sys

The absence of the fixedctr member leads to an incorrect hwc->event_base
value on Zhaoxin CPUs, causing a discrepancy in the instruction count
reported by perf stat. This commit resolves the instruction count issue
by properly initializing the fixedctr member.

Fixes: 149fd4712bcd ("perf/x86/intel: Support Perfmon MSRs aliasing")

Signed-off-by: tanze <tanze@kylinos.cn>
---
 arch/x86/events/zhaoxin/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/events/zhaoxin/core.c b/arch/x86/events/zhaoxin/core.c
index 4bdfcf091200..3fc3f9abece9 100644
--- a/arch/x86/events/zhaoxin/core.c
+++ b/arch/x86/events/zhaoxin/core.c
@@ -467,6 +467,7 @@ static const struct x86_pmu zhaoxin_pmu __initconst = {
 	.schedule_events	= x86_schedule_events,
 	.eventsel		= MSR_ARCH_PERFMON_EVENTSEL0,
 	.perfctr		= MSR_ARCH_PERFMON_PERFCTR0,
+	.fixedctr		= MSR_ARCH_PERFMON_FIXED_CTR0,
 	.event_map		= zhaoxin_pmu_event_map,
 	.max_events		= ARRAY_SIZE(zx_pmon_event_map),
 	.apic			= 1,
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2025-10-15  8:55 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-06-19  3:19 [PATCH] perf/x86/zhaoxin: Fix instructions error by missing fixedctr member tanze
2025-06-19 14:33 ` Liang, Kan
2025-06-20  1:51   ` [PATCH v2 v2] " tanze
2025-06-20  2:10   ` [PATCH 0/1] CANCELLED: [PATCH " tanze
2025-06-20  2:19   ` tanze
2025-06-20  2:37   ` [PATCH v3] " tanze
2025-09-30  2:49     ` Mi, Dapeng
2025-10-15  8:55       ` tanze
2025-09-28  9:44 ` [PATCH] " tanze

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