From: Anshuman Khandual <anshuman.khandual@arm.com>
To: "Rob Herring (Arm)" <robh@kernel.org>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Jonathan Corbet <corbet@lwn.net>, Marc Zyngier <maz@kernel.org>,
Oliver Upton <oliver.upton@linux.dev>,
Joey Gouly <joey.gouly@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
James Clark <james.clark@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, kvmarm@lists.linux.dev
Subject: Re: [PATCH v19 03/11] perf: arm_pmuv3: Don't disable counter in armv8pmu_enable_event()
Date: Mon, 3 Feb 2025 12:08:35 +0530 [thread overview]
Message-ID: <8584f5cc-70b0-46a0-9582-8d7b4d491ba6@arm.com> (raw)
In-Reply-To: <20250202-arm-brbe-v19-v19-3-1c1300802385@kernel.org>
On 2/3/25 06:12, Rob Herring (Arm) wrote:
> From: Mark Rutland <mark.rutland@arm.com>
>
> Currently armv8pmu_enable_event() starts by disabling the event counter
> it has been asked to enable. This should not be necessary as the counter
> (and the PMU as a whole) should not be active when
> armv8pmu_enable_event() is called.
Makes sense.
>
> Remove the redundant call to armv8pmu_disable_event_counter(). At the
> same time, remove the comment immeditately above as everything it says
s/immeditately/immediately
> is obvious from the function names below.
But should this comment drop change be folded into the next patch which
exclusively drops all obviously redundant disable/enable comments.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---
> drivers/perf/arm_pmuv3.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
> index 9ebc950559c0..5406b9ca591a 100644
> --- a/drivers/perf/arm_pmuv3.c
> +++ b/drivers/perf/arm_pmuv3.c
> @@ -795,11 +795,6 @@ static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu)
>
> static void armv8pmu_enable_event(struct perf_event *event)
> {
> - /*
> - * Enable counter and interrupt, and set the counter to count
> - * the event that we're interested in.
> - */
> - armv8pmu_disable_event_counter(event);
> armv8pmu_write_event_type(event);
> armv8pmu_enable_event_irq(event);
> armv8pmu_enable_event_counter(event);
>
Otherwise LGTM.
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
next prev parent reply other threads:[~2025-02-03 6:40 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-03 0:42 [PATCH v19 00/11] arm64/perf: Enable branch stack sampling Rob Herring (Arm)
2025-02-03 0:42 ` [PATCH v19 01/11] perf: arm_pmuv3: Call kvm_vcpu_pmu_resync_el0() before enabling counters Rob Herring (Arm)
2025-02-03 4:07 ` Anshuman Khandual
2025-02-03 0:42 ` [PATCH v19 02/11] perf: arm_pmu: Don't disable counter in armpmu_add() Rob Herring (Arm)
2025-02-03 6:04 ` Anshuman Khandual
2025-02-03 0:42 ` [PATCH v19 03/11] perf: arm_pmuv3: Don't disable counter in armv8pmu_enable_event() Rob Herring (Arm)
2025-02-03 6:38 ` Anshuman Khandual [this message]
2025-02-03 0:42 ` [PATCH v19 04/11] perf: arm_v7_pmu: Drop obvious comments for enabling/disabling counters and interrupts Rob Herring (Arm)
2025-02-03 4:09 ` Anshuman Khandual
2025-02-03 0:42 ` [PATCH v19 05/11] perf: arm_v7_pmu: Don't disable counter in (armv7|krait_|scorpion_)pmu_enable_event() Rob Herring (Arm)
2025-02-03 6:54 ` Anshuman Khandual
2025-02-03 0:43 ` [PATCH v19 06/11] perf: apple_m1: Don't disable counter in m1_pmu_enable_event() Rob Herring (Arm)
2025-02-03 8:10 ` Anshuman Khandual
2025-02-03 0:43 ` [PATCH v19 07/11] perf: arm_pmu: Move PMUv3-specific data Rob Herring (Arm)
2025-02-03 8:16 ` Anshuman Khandual
2025-02-03 0:43 ` [PATCH v19 08/11] arm64/sysreg: Add BRBE registers and fields Rob Herring (Arm)
2025-02-03 8:32 ` Anshuman Khandual
2025-02-03 0:43 ` [PATCH v19 09/11] arm64: Handle BRBE booting requirements Rob Herring (Arm)
2025-02-03 8:47 ` Anshuman Khandual
2025-02-12 12:10 ` Leo Yan
2025-02-12 21:21 ` Rob Herring
2025-02-13 12:27 ` Leo Yan
2025-02-03 0:43 ` [PATCH v19 10/11] KVM: arm64: nvhe: Disable branch generation in nVHE guests Rob Herring (Arm)
2025-02-03 9:16 ` Anshuman Khandual
2025-02-03 11:28 ` James Clark
2025-02-13 17:03 ` Leo Yan
2025-02-13 23:16 ` Rob Herring
2025-02-14 9:55 ` Leo Yan
2025-02-18 14:17 ` Rob Herring
2025-02-03 0:43 ` [PATCH v19 11/11] perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE) Rob Herring (Arm)
2025-02-03 16:53 ` James Clark
2025-02-03 17:58 ` Rob Herring
2025-02-04 12:02 ` James Clark
2025-02-04 15:03 ` Rob Herring
2025-02-05 14:38 ` James Clark
2025-02-05 14:51 ` James Clark
2025-02-05 16:15 ` Rob Herring
2025-02-06 12:58 ` James Clark
2025-02-12 18:52 ` Leo Yan
2025-02-12 19:00 ` Leo Yan
2025-02-13 16:16 ` Leo Yan
2025-02-13 17:13 ` Rob Herring
2025-02-13 17:45 ` Leo Yan
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