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From: Zide Chen <zide.chen@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@linux.intel.com>,
	Zide Chen <zide.chen@intel.com>
Subject: [PATCH 1/6] perf/x86/intel/uncore: Fix discovery unit lookup for multi-die systems
Date: Mon, 11 May 2026 16:05:22 -0700	[thread overview]
Message-ID: <20260511230527.26096-2-zide.chen@intel.com> (raw)
In-Reply-To: <20260511230527.26096-1-zide.chen@intel.com>

In uncore_find_add_unit(), PMON units with the same unit ID may be
added to the uncore discovery RB tree for different dies.  These units
are distinguished by node->die.

However, intel_generic_uncore_box_ctl() uses fixes die ID -1 when
looking up the discovery unit, which may retrieve the wrong node on
multi-die systems.

Use box->dieid instead so the correct discovery unit is selected.

No functional issue has been observed so far because currently supported
platforms happen to use the same unit control register for such units.

Fixes: b1d9ea2e1ca4 ("perf/x86/uncore: Apply the unit control RB tree to MSR uncore units")
Signed-off-by: Zide Chen <zide.chen@intel.com>
---
 arch/x86/events/intel/uncore_discovery.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore_discovery.c b/arch/x86/events/intel/uncore_discovery.c
index 583cbd06b9b8..1d22d7c00ee0 100644
--- a/arch/x86/events/intel/uncore_discovery.c
+++ b/arch/x86/events/intel/uncore_discovery.c
@@ -481,7 +481,7 @@ static u64 intel_generic_uncore_box_ctl(struct intel_uncore_box *box)
 	struct intel_uncore_discovery_unit *unit;
 
 	unit = intel_uncore_find_discovery_unit(box->pmu->type->boxes,
-						-1, box->pmu->pmu_idx);
+						box->dieid, box->pmu->pmu_idx);
 	if (WARN_ON_ONCE(!unit))
 		return 0;
 
-- 
2.54.0


  reply	other threads:[~2026-05-11 23:14 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-11 23:05 [PATCH 0/6] perf/x86/intel/uncore: Bug fixes and cleanups Zide Chen
2026-05-11 23:05 ` Zide Chen [this message]
2026-05-11 23:05 ` [PATCH 2/6] perf/x86/intel/uncore: Fix PCI device refcount leak in UPI discovery Zide Chen
2026-05-12  9:27   ` Mi, Dapeng
2026-05-12 17:35     ` Chen, Zide
2026-05-11 23:05 ` [PATCH 3/6] perf/x86/intel/uncore: Defer ADL global PMON enable to enable_box() Zide Chen
2026-05-11 23:05 ` [PATCH 4/6] perf/x86/intel/uncore: Move die_to_cpu() to uncore.c Zide Chen
2026-05-11 23:05 ` [PATCH 5/6] perf/x86/intel/uncore: Fix uncore_die_to_cpu() for offline dies Zide Chen
2026-05-11 23:05 ` [PATCH 6/6] perf/x86/intel/uncore: Implement global init callback for GNR uncore Zide Chen

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