Re: [PATCH] arm_pmu: Drop redundant armpmu->map_event() in armpmu_event_init()

From: Mark Rutland
Date: Thu Dec 01 2022 - 07:24:46 EST


On Wed, Nov 30, 2022 at 02:03:50PM +0530, Anshuman Khandual wrote:
> __hw_perf_event_init() already calls armpmu->map_event() callback, and also
> returns its error code including -ENOENT, along with a debug callout. Hence
> an additional armpmu->map_event() check for -ENOENT is redundant.

Hmm; it looks like this has been redundant since commit:

e1f431b57ef9e4a6 ("ARM: perf: refactor event mapping")

... and was an oversight on my behalf.

This looks fine to me, so FWIW:

Acked-by: Mark Rutland <mark.rutland@xxxxxxx>

Mark.

>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> This applies on v6.1-rc6
>
> drivers/perf/arm_pmu.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index 6538cec1a601..4be6869005f1 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -529,10 +529,6 @@ static int armpmu_event_init(struct perf_event *event)
> return -EOPNOTSUPP;
> }
> }
> -
> - if (armpmu->map_event(event) == -ENOENT)
> - return -ENOENT;
> -
> return __hw_perf_event_init(event);
> }
>
> --
> 2.25.1
>