[tip: perf/core] perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities

From: tip-bot2 for Dapeng Mi

Date: Tue Jun 30 2026 - 05:09:57 EST


The following commit has been merged into the perf/core branch of tip:

Commit-ID: 9acfcb9b30b6c32ec0d8baad8b7c154120d4cff2
Gitweb: https://git.kernel.org/tip/9acfcb9b30b6c32ec0d8baad8b7c154120d4cff2
Author: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 12 Jun 2026 17:01:07 +08:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 30 Jun 2026 10:57:05 +02:00

perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities

AnyThread mode deprecation is enumerated by CPUID.0AH:EDX[15] instead of
PERF_CAPABILITIES MSR. It's not a good practice to define a bit to
represent "anythread deprecation" in perf_capabilities. It leads to the
anythread_deprecated bit could be overwritten by the real value of
PERF_CAPABILITIES MSR, just like the below code in update_pmu_cap() does.

if (!intel_pmu_broken_perf_cap()) {
/* Perf Metric (Bit 15) and PEBS via PT (Bit 16) are hybrid enumeration */
rdmsrq(MSR_IA32_PERF_CAPABILITIES, hybrid(pmu, intel_cap).capabilities);
}

It leads to the anythread_deprecated bit is cleared to 0 and the "any"
attribute is incorrectly shown in the /sys/devices/cpu/format/ folder on
these support Perfmon v6 platforms, like Clearwater Forest.

$grep . /sys/devices/cpu/format/*
/sys/devices/cpu/format/acr_mask:config2:0-63
/sys/devices/cpu/format/any:config:21
/sys/devices/cpu/format/cmask:config:24-31

So remove the anythread_deprecated bit from perf_capabilities structure
and directly depends on CPUID.0AH:EDX[15] to judge if anythread is
deprecated.

Fixes: cadbaa039b99 ("perf/x86/intel: Make anythread filter support conditional")
Reported-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Zide Chen <zide.chen@xxxxxxxxx>
Reviewed-by: Thomas Falcon <thomas.falcon@xxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://patch.msgid.link/20260612090114.3188886-2-dapeng1.mi@xxxxxxxxxxxxxxx
---
arch/x86/events/intel/core.c | 10 +++-------
arch/x86/events/perf_event.h | 2 +-
2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 2b35483..465c414 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -7947,12 +7947,6 @@ __init int intel_pmu_init(void)

x86_add_quirk(intel_arch_events_quirk); /* Install first, so it runs last */

- if (version >= 5) {
- x86_pmu.intel_cap.anythread_deprecated = edx.split.anythread_deprecated;
- if (x86_pmu.intel_cap.anythread_deprecated)
- pr_cont(" AnyThread deprecated, ");
- }
-
/* The perf side of core PMU is ready to support the mediated vPMU. */
x86_get_pmu(smp_processor_id())->capabilities |= PERF_PMU_CAP_MEDIATED_VPMU;

@@ -8829,8 +8823,10 @@ __init int intel_pmu_init(void)
&x86_pmu.intel_ctrl);

/* AnyThread may be deprecated on arch perfmon v5 or later */
- if (x86_pmu.intel_cap.anythread_deprecated)
+ if (version >= 5 && edx.split.anythread_deprecated) {
x86_pmu.format_attrs = intel_arch_formats_attr;
+ pr_cont("AnyThread deprecated, ");
+ }

intel_pmu_check_event_constraints_all(NULL);

diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index eae24bb..5902a29 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -668,7 +668,7 @@ union perf_capabilities {
u64 perf_metrics:1;
u64 pebs_output_pt_available:1;
u64 pebs_timing_info:1;
- u64 anythread_deprecated:1;
+ u64 __reserved:1;
u64 rdpmc_metrics_clear:1;
};
u64 capabilities;