From: Dave Chinner <david@fromorbit.com>
To: Brian Foster <bfoster@redhat.com>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH 2/8] xfs: separate CIL commit record IO
Date: Fri, 5 Mar 2021 11:44:58 +1100 [thread overview]
Message-ID: <20210305004458.GU4662@dread.disaster.area> (raw)
In-Reply-To: <20210303004119.GL4662@dread.disaster.area>
On Wed, Mar 03, 2021 at 11:41:19AM +1100, Dave Chinner wrote:
> On Mon, Mar 01, 2021 at 10:19:36AM -0500, Brian Foster wrote:
> > On Tue, Feb 23, 2021 at 02:34:36PM +1100, Dave Chinner wrote:
> > That aside, this iteration logic all seems a bit overengineered to me.
> > We have the commit record iclog of the current checkpoint and thus the
> > immediately previous iclog in the ring. We know that previous record
> > isn't earlier than start_lsn because the caller confirmed that start_lsn
> > != commit_lsn. We also know that iclog can't become dirty -> active
> > until it and all previous iclog writes have completed because the
> > callback ordering implemented by xlog_state_do_callback() won't clean
> > the iclog until that point. Given that, can't this whole thing be
> > replaced with a check of iclog->prev to either see if it's been cleaned
> > or to otherwise xlog_wait() for that condition and return?
>
> Maybe. I was more concerned about ensuring that it did the right
> thing so I checked all the things that came to mind. There was more
> than enough compexity in other parts of this patchset to fill my
> brain that minimal implementation were not a concern. I'll go take
> another look at it.
Ok, so we can just use xlog_wait_on_iclog() here. I didn't look too
closely at the implementation of that function, just took the
comment above it at face value that it only waited for an iclog to
hit the disk.
We actually have two different iclog IO completion wait points - one
to wait for an iclog to hit the disk, and one to wait for hit the
disk and run completion callbacks. i.e. one is not ordered against
other iclogs and the other is strictly ordered.
The ordered version runs completion callbacks before waking waiters
thereby guaranteeing all previous iclog have been completed before
completing the current iclog and waking waiters.
The CIL code needs the latter, so yes, this can be simplified down
to a single xlog_wait_on_iclog(commit_iclog->ic_prev); call from the
CIL.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2021-03-05 0:45 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 3:34 [PATCH v2] xfs: various log stuff Dave Chinner
2021-02-23 3:34 ` [PATCH 1/8] xfs: log stripe roundoff is a property of the log Dave Chinner
2021-02-23 10:29 ` Chandan Babu R
2021-02-24 20:14 ` Darrick J. Wong
2021-02-25 8:32 ` Christoph Hellwig
2021-03-01 15:13 ` Brian Foster
2021-02-23 3:34 ` [PATCH 2/8] xfs: separate CIL commit record IO Dave Chinner
2021-02-23 12:12 ` Chandan Babu R
2021-02-24 20:34 ` Darrick J. Wong
2021-02-24 21:44 ` Dave Chinner
2021-02-24 23:06 ` Darrick J. Wong
2021-02-25 8:34 ` Christoph Hellwig
2021-02-25 20:47 ` Dave Chinner
2021-03-01 9:09 ` Christoph Hellwig
2021-03-03 0:11 ` Dave Chinner
2021-02-26 2:48 ` Darrick J. Wong
2021-02-28 16:36 ` Brian Foster
2021-02-28 23:46 ` Dave Chinner
2021-03-01 15:33 ` Brian Foster
2021-03-01 15:19 ` Brian Foster
2021-03-03 0:41 ` Dave Chinner
2021-03-03 15:22 ` Brian Foster
2021-03-04 22:57 ` Dave Chinner
2021-03-05 0:44 ` Dave Chinner [this message]
2021-02-23 3:34 ` [PATCH 3/8] xfs: move and rename xfs_blkdev_issue_flush Dave Chinner
2021-02-23 12:57 ` Chandan Babu R
2021-02-24 20:45 ` Darrick J. Wong
2021-02-24 22:01 ` Dave Chinner
2021-02-25 8:36 ` Christoph Hellwig
2021-02-23 3:34 ` [PATCH 4/8] xfs: async blkdev cache flush Dave Chinner
2021-02-23 5:29 ` Chaitanya Kulkarni
2021-02-23 14:02 ` Chandan Babu R
2021-02-24 20:51 ` Darrick J. Wong
2021-02-23 3:34 ` [PATCH 5/8] xfs: CIL checkpoint flushes caches unconditionally Dave Chinner
2021-02-24 7:16 ` Chandan Babu R
2021-02-24 20:57 ` Darrick J. Wong
2021-02-25 8:42 ` Christoph Hellwig
2021-02-25 21:07 ` Dave Chinner
2021-02-23 3:34 ` [PATCH 6/8] xfs: remove need_start_rec parameter from xlog_write() Dave Chinner
2021-02-24 7:17 ` Chandan Babu R
2021-02-24 20:59 ` Darrick J. Wong
2021-02-25 8:49 ` Christoph Hellwig
2021-02-25 20:55 ` Dave Chinner
2021-02-23 3:34 ` [PATCH 7/8] xfs: journal IO cache flush reductions Dave Chinner
2021-02-23 8:05 ` [PATCH 7/8 v2] " Dave Chinner
2021-02-24 12:27 ` Chandan Babu R
2021-02-24 20:32 ` Dave Chinner
2021-02-24 21:13 ` Darrick J. Wong
2021-02-24 22:03 ` Dave Chinner
2021-02-25 4:09 ` Chandan Babu R
2021-02-25 7:13 ` Chandan Babu R
2021-03-01 5:44 ` Dave Chinner
2021-03-01 5:56 ` Dave Chinner
2021-02-25 8:58 ` Christoph Hellwig
2021-02-25 21:06 ` Dave Chinner
2021-03-01 19:29 ` Brian Foster
2021-02-23 3:34 ` [PATCH 8/8] xfs: Fix CIL throttle hang when CIL space used going backwards Dave Chinner
2021-02-24 21:18 ` Darrick J. Wong
2021-02-24 22:05 ` Dave Chinner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210305004458.GU4662@dread.disaster.area \
--to=david@fromorbit.com \
--cc=bfoster@redhat.com \
--cc=linux-xfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.