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Date:   Tue, 17 Oct 2023 04:00:15 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Kairui Song <kasong@tencent.com>
Cc:     linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
        "Huang, Ying" <ying.huang@intel.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/swap: avoid a xa load for swapout path
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References: <20231017011728.37508-1-ryncsn@gmail.com>
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On Tue, Oct 17, 2023 at 09:17:28AM +0800, Kairui Song wrote:
> From: Kairui Song <kasong@tencent.com>
> 
> A variable is never used for swapout path (shadowp is NULL) and compiler
> is unable to optimize out the unneeded load since it's a function call.
> 
> Signed-off-by: Kairui Song <kasong@tencent.com>

Reviewed-by: Matthew Wilcox (Oracle)

Possibly worth adding a reference to
3852f6768ede ("mm/swapcache: support to handle the shadow entries")

Not sure it's worth a Fixes:, but that's where it was introduced.