linux-kernel - [PATCH] perf/x86/zhaoxin: Fix instructions error by missing fixedctr member

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Message-Id: <20250619031947.1111196-1-tanze@kylinos.cn>
Date: Thu, 19 Jun 2025 11:19:47 +0800
From: tanze <tanze@...inos.cn>
To: peterz@...radead.org,
	kan.liang@...ux.intel.com
Cc: linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	x86@...nel.org,
	tanze <tanze@...inos.cn>
Subject: [PATCH] perf/x86/zhaoxin: Fix instructions error by missing fixedctr member

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@...inos.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