From: Dave Chinner <david@fromorbit.com>
To: Yang Shi <yang.shi@linux.alibaba.com>
Cc: mgorman@techsingularity.net, tytso@mit.edu,
adilger.kernel@dilger.ca, darrick.wong@oracle.com,
dchinner@redhat.com, akpm@linux-foundation.org,
linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] fs: xfs: use BUG_ON if writepage call comes from direct reclaim
Date: Tue, 3 Jul 2018 14:37:38 +1000 [thread overview]
Message-ID: <20180703043738.GG2234@dastard> (raw)
In-Reply-To: <1530591079-33813-2-git-send-email-yang.shi@linux.alibaba.com>
On Tue, Jul 03, 2018 at 12:11:19PM +0800, Yang Shi wrote:
> direct reclaim doesn't write out filesystem page, only kswapd could do
> this. So, if it is called from direct relaim, it is definitely a bug.
>
> And, Mel Gorman mentioned "Ultimately, this will be a BUG_ON." in commit
> 94054fa3fca1fd78db02cb3d68d5627120f0a1d4 ("xfs: warn if direct reclaim
> tries to writeback pages"),
>
> It has been many years since that commit, so it should be safe to
> elevate WARN_ON to BUG_ON now.
NACK.
The existing code warns and then handles the situation gracefully -
this is the appropriate way to handle incorrect calling contexts.
There is absolutely no good reason to panic production kernels
in situations like this.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2018-07-03 4:37 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-03 4:11 [PATCH 1/2] fs: ext4: use BUG_ON if writepage call comes from direct reclaim Yang Shi
2018-07-03 4:11 ` [PATCH 2/2] fs: xfs: " Yang Shi
2018-07-03 4:37 ` Dave Chinner [this message]
2018-07-03 17:19 ` Darrick J. Wong
2018-07-03 10:39 ` [PATCH 1/2] fs: ext4: " Theodore Y. Ts'o
2018-07-03 17:05 ` Yang Shi
2018-07-03 23:10 ` Yang Shi
2018-07-03 23:10 ` Yang Shi
2018-07-03 23:43 ` Theodore Y. Ts'o
2018-07-04 14:03 ` Michal Hocko
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