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From:   Vinod Koul <vkoul@kernel.org>
To:     dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
        Uros Bizjak <ubizjak@gmail.com>
Cc:     Fenghua Yu <fenghua.yu@intel.com>,
        Dave Jiang <dave.jiang@intel.com>
In-Reply-To: <20230703145346.5206-1-ubizjak@gmail.com>
References: <20230703145346.5206-1-ubizjak@gmail.com>
Subject: Re: [PATCH] dmaengine:idxd: Use local64_try_cmpxchg in
 perfmon_pmu_event_update
Message-Id: <169091550434.69468.5073669723336926533.b4-ty@kernel.org>
Date:   Wed, 02 Aug 2023 00:15:04 +0530
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On Mon, 03 Jul 2023 16:52:37 +0200, Uros Bizjak wrote:
> Use local64_try_cmpxchg instead of local64_cmpxchg (*ptr, old, new) == old
> in perfmon_pmu_event_update.  x86 CMPXCHG instruction returns success in
> ZF flag, so this change saves a compare after cmpxchg (and related move
> instruction in front of cmpxchg).
> 
> Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
> fails. There is no need to re-read the value in the loop.
> 
> [...]

Applied, thanks!

[1/1] dmaengine:idxd: Use local64_try_cmpxchg in perfmon_pmu_event_update
      commit: cae701b9ccf128edea26982f73178087fc3ad180

Best regards,
-- 
~Vinod