linux-kernel - [tip: perf/core] arm_pmu: Remove unused PERF_PMU_CAP_HETEROGENEOUS

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Message-ID: <169079877090.28540.17067379324093297410.tip-bot2@tip-bot2>
Date:   Mon, 31 Jul 2023 10:19:30 -0000
From:   "tip-bot2 for James Clark" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     James Clark <james.clark@....com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Anshuman Khandual <anshuman.khandual@....com>,
        Ian Rogers <irogers@...gle.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: perf/core] arm_pmu: Remove unused
 PERF_PMU_CAP_HETEROGENEOUS_CPUS capability

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

Commit-ID:     80391d8c387d406e2ec79776ec834666ab9611b0
Gitweb:        https://git.kernel.org/tip/80391d8c387d406e2ec79776ec834666ab9611b0
Author:        James Clark <james.clark@....com>
AuthorDate:    Mon, 24 Jul 2023 14:44:58 +01:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Wed, 26 Jul 2023 12:28:47 +02:00

arm_pmu: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability

Since commit bd2756811766 ("perf: Rewrite core context handling") the
relationship between perf_event_context and PMUs has changed so that
the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally
silenced no longer exists.

Remove the capability and associated comment to avoid confusion that it
actually influences any perf core behavior. This change should be a
no-op.

Signed-off-by: James Clark <james.clark@....com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@....com>
Acked-by: Ian Rogers <irogers@...gle.com>
Link: https://lore.kernel.org/r/20230724134500.970496-4-james.clark@arm.com
---
 drivers/perf/arm_pmu.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 2e79201..d712a19 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -877,15 +877,12 @@ struct arm_pmu *armpmu_alloc(void)
 		.attr_groups	= pmu->attr_groups,
 		/*
 		 * This is a CPU PMU potentially in a heterogeneous
-		 * configuration (e.g. big.LITTLE). This is not an uncore PMU,
-		 * and we have taken ctx sharing into account (e.g. with our
-		 * pmu::filter callback and pmu::event_init group validation).
-		 *
+		 * configuration (e.g. big.LITTLE) so
 		 * PERF_PMU_CAP_EXTENDED_HW_TYPE is required to open
 		 * PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE events on a
 		 * specific PMU.
 		 */
-		.capabilities	= PERF_PMU_CAP_HETEROGENEOUS_CPUS | PERF_PMU_CAP_EXTENDED_REGS |
+		.capabilities	= PERF_PMU_CAP_EXTENDED_REGS |
 				  PERF_PMU_CAP_EXTENDED_HW_TYPE,
 	};