From: Christoph Hellwig <hch@lst.de>
To: Brian Foster <bfoster@redhat.com>
Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" <djwong@kernel.org>,
Christoph Hellwig <hch@lst.de>
Subject: Re: xfs ioend batching log reservation deadlock
Date: Mon, 29 Mar 2021 07:45:13 +0200 [thread overview]
Message-ID: <20210329054513.GA26736@lst.de> (raw)
In-Reply-To: <YF4AOto30pC/0FYW@bfoster>
On Fri, Mar 26, 2021 at 11:39:38AM -0400, Brian Foster wrote:
> 1. Optimize current append transaction processing with an inode field as
> noted above.
>
> 2. Replace the submission side append transaction entirely with a flag
> or some such on the ioend that allocates the transaction at completion
> time, but otherwise preserves batching behavior instituted in patch 1.
I'm pretty sure I had a patch to kill off the transaction reservation
a while ago and Dave objected, mostly in performance grounds in that
we might have tons of reservations coming from the I/O completion
workqueue that would all be blocked on the transaction reservations.
This would probably be much better with the ioend merging, which should
significantly reduce the amount of transactions reservations - to probably
not more than common workloads using unwritten extents.
I'm all for killing the transaction pre-reservations as they have created
a lot of pain for us.
prev parent reply other threads:[~2021-03-29 5:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 15:39 xfs ioend batching log reservation deadlock Brian Foster
2021-03-26 17:32 ` Darrick J. Wong
2021-03-26 18:13 ` Brian Foster
2021-03-29 2:28 ` Dave Chinner
2021-03-29 18:04 ` Brian Foster
2021-03-29 23:51 ` Dave Chinner
2021-03-30 14:42 ` Brian Foster
2021-03-30 23:57 ` Dave Chinner
2021-03-31 12:26 ` Brian Foster
2021-03-29 5:45 ` Christoph Hellwig [this message]
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