linux-kernel - Re: [PATCH] perf/arm-cci: Slightly optimize cci_pmu_sync

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Message-Id: <168597318508.3035025.8084369387360495178.b4-ty@kernel.org>
Date:   Mon,  5 Jun 2023 17:35:02 +0100
From:   Will Deacon <will@...nel.org>
To:     Mark Rutland <mark.rutland@....com>,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     catalin.marinas@....com, kernel-team@...roid.com,
        Will Deacon <will@...nel.org>, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] perf/arm-cci: Slightly optimize cci_pmu_sync_counters()

On Thu, 20 Apr 2023 22:27:24 +0200, Christophe JAILLET wrote:
> When the 'mask' bitmap is cleared, it is better to use its full maximum
> size instead of only the needed size.
> This lets the compiler optimize it because the size is now known at compile
> time. HW_CNTRS_MAX is small (i.e. currently 9), so a call to memset() is
> saved.
> 
> Also, as 'mask' is local to the function, the non-atomic __set_bit() can
> also safely be used here.
> 
> [...]

Applied to will (for-next/perf), thanks!

[1/1] perf/arm-cci: Slightly optimize cci_pmu_sync_counters()
      https://git.kernel.org/will/c/f818947a0618

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev