From: Dapeng Mi <dapeng1.mi@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
Eranian Stephane <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
Dapeng Mi <dapeng1.mi@intel.com>, Zide Chen <zide.chen@intel.com>,
Falcon Thomas <thomas.falcon@intel.com>,
Xudong Hao <xudong.hao@intel.com>,
Dapeng Mi <dapeng1.mi@linux.intel.com>,
stable@vger.kernel.org
Subject: [Patch v3 1/8] perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities
Date: Fri, 12 Jun 2026 17:01:07 +0800 [thread overview]
Message-ID: <20260612090114.3188886-2-dapeng1.mi@linux.intel.com> (raw)
In-Reply-To: <20260612090114.3188886-1-dapeng1.mi@linux.intel.com>
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.
Cc: stable@vger.kernel.org
Reported-by: Namhyung Kim <namhyung@kernel.org>
Fixes: cadbaa039b99 ("perf/x86/intel: Make anythread filter support conditional")
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Reviewed-by: Zide Chen <zide.chen@intel.com>
Reviewed-by: Thomas Falcon <thomas.falcon@intel.com>
---
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 0217e701aeeb..ea3ab3050a3b 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -7946,12 +7946,6 @@ __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;
@@ -8828,8 +8822,10 @@ __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 eae24bb35dc1..5902a297daa1 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;
--
2.34.1
next prev parent reply other threads:[~2026-06-12 9:06 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-12 9:01 [Patch v3 0/8] perf/x86: Miscellaneous PMU bug fixes Dapeng Mi
2026-06-12 9:01 ` Dapeng Mi [this message]
2026-06-12 9:46 ` [Patch v3 1/8] perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities Peter Zijlstra
2026-06-15 0:59 ` Mi, Dapeng
2026-06-15 3:28 ` Mi, Dapeng
2026-06-16 10:02 ` Peter Zijlstra
2026-06-17 0:14 ` Mi, Dapeng
2026-06-12 9:01 ` [Patch v3 2/8] perf/x86/intel: Keep cap_user_rdpmc in sync with RDPMC user-disable state Dapeng Mi
2026-06-12 9:01 ` [Patch v3 3/8] perf/x86/intel: Fallback to sw branch type decoding if no hw decoding Dapeng Mi
2026-06-12 9:21 ` sashiko-bot
2026-06-15 1:00 ` Mi, Dapeng
2026-06-15 1:03 ` Mi, Dapeng
2026-06-12 9:01 ` [Patch v3 4/8] perf/x86/intel: Fix kernel address leakages in LBR stack Dapeng Mi
2026-06-12 9:18 ` sashiko-bot
2026-06-15 1:01 ` Mi, Dapeng
2026-06-12 9:01 ` [Patch v3 5/8] perf/x86/intel: Validate the return value of intel_pmu_init_hybrid() Dapeng Mi
2026-06-12 9:31 ` sashiko-bot
2026-06-15 1:08 ` Mi, Dapeng
2026-06-12 9:01 ` [Patch v3 6/8] perf/x86/intel: Drop fixed-counter PEBS constraints for baseline PEBS Dapeng Mi
2026-06-12 9:01 ` [Patch v3 7/8] perf/core: Fix kernel register info leak via hardware skid Dapeng Mi
2026-06-12 9:01 ` [Patch v3 8/8] perf/core: Check kernel access when kernel callchains are requested Dapeng Mi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260612090114.3188886-2-dapeng1.mi@linux.intel.com \
--to=dapeng1.mi@linux.intel.com \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=ak@linux.intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=dapeng1.mi@intel.com \
--cc=eranian@google.com \
--cc=irogers@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=stable@vger.kernel.org \
--cc=thomas.falcon@intel.com \
--cc=xudong.hao@intel.com \
--cc=zide.chen@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.