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Date:   Tue, 24 Oct 2023 07:53:43 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Jan Kara <jack@suse.cz>
Cc:     Hugh Dickins <hughd@google.com>,
        Matthew Wilcox <willy@infradead.org>,
        Hui Zhu <teawater@antgroup.com>, Theodore Ts'o <tytso@mit.edu>,
        linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH] ext4: add __GFP_NOWARN to GFP_NOWAIT in readahead
Message-Id: <20231024075343.e5f0bd0d99962a4f0e32d1a0@linux-foundation.org>
In-Reply-To: <20231024100318.muhq5omspyegli4c@quack3>
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        <20231024100318.muhq5omspyegli4c@quack3>
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On Tue, 24 Oct 2023 12:03:18 +0200 Jan Kara <jack@suse.cz> wrote:

> On Mon 23-10-23 23:26:08, Hugh Dickins wrote:
> > Since mm-hotfixes-stable commit e509ad4d77e6 ("ext4: use bdev_getblk() to
> > avoid memory reclaim in readahead path") rightly replaced GFP_NOFAIL
> > allocations by GFP_NOWAIT allocations, I've occasionally been seeing
> > "page allocation failure: order:0" warnings under load: all with
> > ext4_sb_breadahead_unmovable() in the stack.  I don't think those
> > warnings are of any interest: suppress them with __GFP_NOWARN.
> > 
> > Fixes: e509ad4d77e6 ("ext4: use bdev_getblk() to avoid memory reclaim in readahead path")
> > Signed-off-by: Hugh Dickins <hughd@google.com>
> 
> Yeah, makes sense. Just the commit you mention isn't upstream yet so I'm
> not sure whether the commit hash is stable.

e509ad4d77e6 is actually in mm-stable so yes, the hash should be stable.