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Date:   Thu, 21 Feb 2019 14:15:14 +0000
From:   Will Deacon <will.deacon@arm.com>
To:     Waiman Long <longman@redhat.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org, x86@kernel.org,
        Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Tim Chen <tim.c.chen@linux.intel.com>
Subject: Re: [PATCH-tip v2 04/10] locking/rwsem: Micro-optimize
 rwsem_try_read_lock_unqueued()
Message-ID: <20190221141514.GE12696@fuggles.cambridge.arm.com>
References: <1550263810-31947-1-git-send-email-longman@redhat.com>
 <1550263810-31947-5-git-send-email-longman@redhat.com>
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On Fri, Feb 15, 2019 at 03:50:04PM -0500, Waiman Long wrote:
> The atomic_long_cmpxchg_acquire() in rwsem_try_read_lock_unqueued() is
> replaced by atomic_long_try_cmpxchg_acquire() to simpify the code and
> generate slightly better assembly code. There is no functional change.

Might be nice to illustrate the improvement in the commit message, but
it seems that try_cmpxchg is generally preferred for x86, so:

Acked-by: Will Deacon <will.deacon@arm.com>

Will