From: Christoph Hellwig <hch@infradead.org>
To: Dave Chinner <david@fromorbit.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH] [RFC] xfs: byte range buffer dirty region tracking
Date: Tue, 25 Feb 2014 18:15:25 -0800 [thread overview]
Message-ID: <20140226021525.GB26022@infradead.org> (raw)
In-Reply-To: <1393194354-12780-1-git-send-email-david@fromorbit.com>
Interesting. I had a prototype of this supporting just a single
region a while ago, but never managed to get it to pass all recovery
tests. That was before I separated the in-core from the on-disk
log items, though.
> Hence if we just track a signle region, it will almost always cover
> the entire directory buffer - if we only modify a single entry in
> the buffer, then that's a fairly large cost in terms of log space
> and CPU overhead for random individual operations. If we decide that
> we are going to use a single range, then we may as well just use the
> dirty flag and log the entire buffer every time.
Which might not be an all that bad idea given how much log bandwith
we have available. Defintively would be interesting to instrument
and benchmark it vs the 4 regions version.
Note that we probably should also introduce a log incompat feature to
just log the range instead of converting it to the old bitmap for v5
filesystems.
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2014-02-26 2:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-23 22:25 [PATCH] [RFC] xfs: byte range buffer dirty region tracking Dave Chinner
2014-02-26 2:15 ` Christoph Hellwig [this message]
2014-02-26 5:44 ` Dave Chinner
2014-02-26 14:53 ` Mark Tinguely
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=20140226021525.GB26022@infradead.org \
--to=hch@infradead.org \
--cc=david@fromorbit.com \
--cc=xfs@oss.sgi.com \
/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