From: Christoph Hellwig <hch@lst.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 2/2] xfs: reduce ilock acquisitions in xfs_file_fsync
Date: Tue, 26 Jan 2021 07:56:56 +0100 [thread overview]
Message-ID: <20210126065656.GB26958@lst.de> (raw)
In-Reply-To: <20210123064139.GA709@lst.de>
On Sat, Jan 23, 2021 at 07:41:39AM +0100, Christoph Hellwig wrote:
> > In fact, I wonder if we need to do anything other than just use
> > REQ_FUA unconditionally in iomap for this situation, as the block
> > layer will translate REQ_FUA to a write+post-flush if the device
> > doesn't support FUA writes directly.
> >
> > You're thoughts on that, Christoph?
>
> For the pure overwrite O_DIRECT + O_DSYNC case we'd get away with just
> a flush. And using REQ_FUA will get us there, so it might be worth
> a try.
And looking at this a little more, while just using REQ_FUA would
work it would be rather suboptimal for many cases, as the block layer
flush state machine would do a flush for every bio. So for each
O_DIRECT + O_DSYNC write that generates more than one bio we'd grow
extra flushes.
next prev parent reply other threads:[~2021-01-26 17:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 16:46 avoid taking the iolock in fsync unless actually needed v2 Christoph Hellwig
2021-01-22 16:46 ` [PATCH 1/2] xfs: refactor xfs_file_fsync Christoph Hellwig
2021-01-22 21:08 ` Dave Chinner
2021-01-22 16:46 ` [PATCH 2/2] xfs: reduce ilock acquisitions in xfs_file_fsync Christoph Hellwig
2021-01-22 21:08 ` Dave Chinner
2021-01-23 6:41 ` Christoph Hellwig
2021-01-26 6:56 ` Christoph Hellwig [this message]
2021-01-25 13:16 ` Brian Foster
2021-01-28 8:00 ` Christoph Hellwig
-- strict thread matches above, loose matches on Subject: below --
2021-01-11 16:15 avoid taking the iolock in fsync unless actually needed Christoph Hellwig
2021-01-11 16:15 ` [PATCH 2/2] xfs: reduce ilock acquisitions in xfs_file_fsync Christoph Hellwig
2021-01-12 15:34 ` Brian Foster
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=20210126065656.GB26958@lst.de \
--to=hch@lst.de \
--cc=david@fromorbit.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox