From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
Subject: Re: [PATCH] memcg: set page->private before calling swap_readpage
Date: Thu, 18 Mar 2021 11:03:10 -0400
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References: <20210318015959.2986837-1-shakeelb@google.com>
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To: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Hugh Dickins <hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Roman Gushchin <guro-b10kYP2dOMg@public.gmane.org>, Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Minchan Kim <minchan-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Heiko Carstens <hca-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org>

On Wed, Mar 17, 2021 at 06:59:59PM -0700, Shakeel Butt wrote:
> The function swap_readpage() (and other functions it call) extracts swap
> entry from page->private. However for SWP_SYNCHRONOUS_IO, the kernel
> skips the swapcache and thus we need to manually set the page->private
> with the swap entry before calling swap_readpage().
> 
> Signed-off-by: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
> Reported-by: Heiko Carstens <hca-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org>

LGTM