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Date:   Fri, 21 Jan 2022 09:51:08 +0000
From:   CGEL <cgel.zte@gmail.com>
To:     Johannes Weiner <hannes@cmpxchg.org>
Cc:     akpm@linux-foundation.org, sfr@canb.auug.org.au,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Yang Yang <yang.yang29@zte.com.cn>
Subject: Re: [PATCH] psi: Treat ksm swapping in copy as memstall
References: <20220116152150.859520-1-yang.yang29@zte.com.cn>
 <YeVdvVVBvrXH5U0L@cmpxchg.org>
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 <YegK7+oKFG8EPRp9@cmpxchg.org>
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 Wed, Jan 19, 2022 at 07:58:23AM -0500, Johannes Weiner wrote:
> On Wed, Jan 19, 2022 at 06:13:54AM +0000, CGEL wrote:
> > I did a test, when we use zram, it takes longer time for ksm copying than
> > swap_readpage(). Ksm copying average takes 147263ns, swap_readpage()
> > average takes 55639ns. So I think this patch is reasonable.
> 
> Ok, that sounds reasonable to me as well. Please add the
> PageWorkingset() check and resubmit the patch. Thanks!
I am a litte confused about adding PageWorkingset(), since I
think ksm_might_need_to_copy() memstall is like swap_readpage()
memstall and swap_readpage() doesn't add PageWorkingset().

Would please make it cleaner? Thanks!