From: Christoph Hellwig <hch@infradead.org>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Brian Foster <bfoster@redhat.com>, linux-xfs@vger.kernel.org
Subject: Re: [PATCH v3 03/17] xfs: simplify inode flush error handling
Date: Fri, 1 May 2020 02:17:30 -0700 [thread overview]
Message-ID: <20200501091730.GA20187@infradead.org> (raw)
In-Reply-To: <20200430183703.GD6742@magnolia>
On Thu, Apr 30, 2020 at 11:37:03AM -0700, Darrick J. Wong wrote:
> TBH I've long wondered why we flush one inode and only then check that
> the icluster buffer is pinned and if so force the log? Did we do that
> for some sort of forward progress guarantee?
>
> I looked at a3f74ffb6d144 (aka when the log force moved here from after
> the iflush_cluster call) but that didn't help me figure out if there's
> some subtlety here I'm missing, or if the ordering here was weird but
> the weirdness didn't matter?
>
> TLDR: I can't tell why it's ok to move the xfs_iflush_int call down past
> the log force. :/
As far as I can tell the log force is to avoid waiting for the buffer
to be unpinned. This is mostly bad when using xfs_bwrite, which we
still do for the xfs_reclaim_inode case, given that xfs_inode_item_push
alredy checks for the pinned inode earlier, and lets the xfsaild handle
the log pushing.
Which means doing the log_force earlier is actually a (practially not
relevant) micro-optimization as it gives the log code a few more
instructions worth of time to push out and complete the log buffer.
Maybe this wants to be split out into a prep patch to better document
the change.
next prev parent reply other threads:[~2020-05-01 9:17 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 17:21 [PATCH v3 00/17] xfs: flush related error handling cleanups Brian Foster
2020-04-29 17:21 ` [PATCH v3 01/17] xfs: refactor failed buffer resubmission into xfsaild Brian Foster
2020-04-30 17:26 ` Darrick J. Wong
2020-04-29 17:21 ` [PATCH v3 02/17] xfs: factor out buffer I/O failure code Brian Foster
2020-04-30 18:16 ` Darrick J. Wong
2020-05-01 7:43 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 03/17] xfs: simplify inode flush error handling Brian Foster
2020-04-30 18:37 ` Darrick J. Wong
2020-05-01 9:17 ` Christoph Hellwig [this message]
2020-05-01 10:17 ` Christoph Hellwig
2020-05-01 17:43 ` Darrick J. Wong
2020-05-01 17:50 ` Christoph Hellwig
2020-05-01 11:22 ` Brian Foster
2020-04-29 17:21 ` [PATCH v3 04/17] xfs: remove unnecessary shutdown check from xfs_iflush() Brian Foster
2020-04-30 18:37 ` Darrick J. Wong
2020-04-29 17:21 ` [PATCH v3 05/17] xfs: reset buffer write failure state on successful completion Brian Foster
2020-04-30 18:41 ` Darrick J. Wong
2020-05-01 7:44 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 06/17] xfs: refactor ratelimited buffer error messages into helper Brian Foster
2020-04-30 18:42 ` Darrick J. Wong
2020-05-01 7:44 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 07/17] xfs: ratelimit unmount time per-buffer I/O error alert Brian Foster
2020-04-30 18:43 ` Darrick J. Wong
2020-04-30 22:07 ` Dave Chinner
2020-05-01 11:24 ` Brian Foster
2020-05-01 7:48 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 08/17] xfs: fix duplicate verification from xfs_qm_dqflush() Brian Foster
2020-04-30 18:45 ` Darrick J. Wong
2020-05-01 11:24 ` Brian Foster
2020-04-29 17:21 ` [PATCH v3 09/17] xfs: abort consistently on dquot flush failure Brian Foster
2020-04-30 18:46 ` Darrick J. Wong
2020-04-29 17:21 ` [PATCH v3 10/17] xfs: acquire ->ail_lock from xfs_trans_ail_delete() Brian Foster
2020-04-30 18:52 ` Darrick J. Wong
2020-05-01 11:25 ` Brian Foster
2020-05-01 7:50 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 11/17] xfs: use delete helper for items expected to be in AIL Brian Foster
2020-04-30 18:54 ` Darrick J. Wong
2020-05-01 7:56 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 12/17] xfs: drop unused shutdown parameter from xfs_trans_ail_remove() Brian Foster
2020-04-30 18:56 ` Darrick J. Wong
2020-05-01 7:57 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 13/17] xfs: combine xfs_trans_ail_[remove|delete]() Brian Foster
2020-04-30 18:58 ` Darrick J. Wong
2020-05-01 8:01 ` Christoph Hellwig
2020-05-01 8:00 ` Christoph Hellwig
2020-05-01 11:25 ` Brian Foster
2020-04-29 17:21 ` [PATCH v3 14/17] xfs: remove unused iflush stale parameter Brian Foster
2020-04-30 18:58 ` Darrick J. Wong
2020-04-29 17:21 ` [PATCH v3 15/17] xfs: random buffer write failure errortag Brian Foster
2020-04-30 18:59 ` Darrick J. Wong
2020-05-01 8:02 ` Christoph Hellwig
2020-04-29 17:21 ` [PATCH v3 16/17] xfs: remove unused shutdown types Brian Foster
2020-04-30 18:59 ` Darrick J. Wong
2020-04-29 17:21 ` [PATCH v3 17/17] xfs: remove unused iget_flags param from xfs_imap_to_bp() Brian Foster
2020-04-30 19:00 ` Darrick J. Wong
2020-05-01 8:03 ` Christoph Hellwig
2020-05-01 11:25 ` Brian Foster
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