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From: Namhyung Kim <namhyung@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Stephane Eranian <eranian@google.com>,
	Dapeng Mi <dapeng1.mi@linux.intel.com>
Subject: [PATCH] perf/x86/intel: Keep anythread_deprecated capability
Date: Mon, 13 Apr 2026 14:29:33 -0700	[thread overview]
Message-ID: <20260413212933.2495502-1-namhyung@kernel.org> (raw)

In update_pmu_cap(), it reads MSR_IA32_PERF_CAPABILITIES on non-MTL CPUs
to update the PMU capabilities.  But it resets the anythread_deprecated
bit on GNR so I can see /sys/bus/event_source/devices/cpu/format/any
even if dmesg says AnyThread is deprecated.

  # dmesg | grep -A10 AnyThread
  [   10.662423] Performance Events: XSAVE Architectural LBR, PEBS fmt5+-baseline,  AnyThread deprecated, Granite Rapids events, 32-deep LBR, full-width counters, Intel PMU driver.
  [   10.663172] ... version:                   5
  [   10.663173] ... bit width:                 48
  [   10.663174] ... generic counters:          8
  [   10.663174] ... generic bitmap:            00000000000000ff
  [   10.663175] ... fixed-purpose counters:    4
  [   10.663176] ... fixed-purpose bitmap:      000000000000000f
  [   10.663176] ... value mask:                0000ffffffffffff
  [   10.663177] ... max period:                00007fffffffffff
  [   10.663178] ... global_ctrl mask:          0001000f000000ff
  [   10.668979] signal: max sigframe size: 11952

I guess it's not intentional and we want to keep deprecating anythread
on these machines.

Fixes: 25c623f41438fafc ("perf/x86/intel: Parse CPUID archPerfmonExt leaves for non-hybrid CPUs")
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 arch/x86/events/intel/core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 4768236c054bbcf8..f1fae640cc8e5991 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -5945,8 +5945,12 @@ static void update_pmu_cap(struct pmu *pmu)
 	}
 
 	if (!intel_pmu_broken_perf_cap()) {
+		bool anythread = hybrid(pmu, intel_cap).anythread_deprecated;
+
 		/* Perf Metric (Bit 15) and PEBS via PT (Bit 16) are hybrid enumeration */
 		rdmsrq(MSR_IA32_PERF_CAPABILITIES, hybrid(pmu, intel_cap).capabilities);
+		/* It seems anythread_deprecated is deleted unintentionally */
+		hybrid(pmu, intel_cap).anythread_deprecated = anythread;
 	}
 }
 
-- 
2.54.0.rc0.605.g598a273b03-goog


             reply	other threads:[~2026-04-13 21:29 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-13 21:29 Namhyung Kim [this message]
2026-04-14  2:09 ` [PATCH] perf/x86/intel: Keep anythread_deprecated capability Mi, Dapeng
2026-04-14  6:56   ` Namhyung Kim

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