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Date:   Thu, 16 Jan 2020 04:27:22 -0800 (PST)
Message-Id: <20200116.042722.153124126288244814.davem@davemloft.net>
To:     zhangshaokun@hisilicon.com
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        jinyuqi@huawei.com, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org,
        edumazet@google.com, guoyang2@huawei.com
Subject: Re: [PATCH] net: optimize cmpxchg in ip_idents_reserve
From:   David Miller <davem@davemloft.net>
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From: Shaokun Zhang <zhangshaokun@hisilicon.com>
Date: Wed, 15 Jan 2020 11:23:40 +0800

> From: Yuqi Jin <jinyuqi@huawei.com>
> 
> atomic_try_cmpxchg is called instead of atomic_cmpxchg that can reduce
> the access number of the global variable @p_id in the loop. Let's
> optimize it for performance.
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Yang Guo <guoyang2@huawei.com>
> Signed-off-by: Yuqi Jin <jinyuqi@huawei.com>
> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>

I doubt this makes any measurable improvement in performance.

If you can document a specific measurable improvement under
a useful set of circumstances for real usage, then put those
details into the commit message and resubmit.

Otherwise, I'm not applying this, sorry.