From: Ben Myers <bpm@sgi.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: jeff.liu@oracle.com, Mark Tinguely <tinguely@sgi.com>,
Chris Mason <chris.mason@oracle.com>,
xfs@oss.sgi.com
Subject: Re: Introduce SEEK_DATA/SEEK_HOLE to XFS V5
Date: Thu, 12 Jan 2012 11:39:59 -0600 [thread overview]
Message-ID: <20120112173959.GU20739@sgi.com> (raw)
In-Reply-To: <20120112164148.GB22223@infradead.org>
On Thu, Jan 12, 2012 at 11:41:48AM -0500, Christoph Hellwig wrote:
> On Thu, Jan 12, 2012 at 09:01:48AM -0600, Mark Tinguely wrote:
> > >Sorry, am was well understood your opinions in this point for now.
> > >IMHO, we can only find and return the data buffer offset at a dirty or
> > >unwritten page once the first page was probed.
> > >
> >
> > From my tests, xfs_bmapi_read() can only find holes if they cross or
> > start on a 64KB boundary. It would be nice if unwritten extents were
> > at least that good at finding holes.
>
> Are you testing on ia64 with 64k blocks? :) xfs_bmapi_read will
> find holes down to block granularity, that's how it's implemented.
> However recent XFS does fairly aggressive preallocation, so you probably
^^^^
it is speculative delay in this case, I think.
-Ben
> won't find small holes unless you explicitly punch them out using
> XFS_IOC_UNRESVSP or fallocate with the hole punch flag.
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2012-01-12 17:40 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-06 13:28 Introduce SEEK_DATA/SEEK_HOLE to XFS V5 Jeff Liu
2012-01-10 17:18 ` Ben Myers
2012-01-11 5:45 ` Jeff Liu
2012-01-11 21:06 ` Mark Tinguely
2012-01-12 16:22 ` Christoph Hellwig
2012-01-12 17:50 ` Ben Myers
2012-01-11 21:07 ` Mark Tinguely
2012-01-12 13:29 ` Jeff Liu
2012-01-12 16:39 ` Christoph Hellwig
2012-01-13 2:14 ` Jeff Liu
2012-01-11 21:12 ` Mark Tinguely
2012-01-12 13:52 ` Jeff Liu
2012-01-12 15:01 ` Mark Tinguely
2012-01-12 16:41 ` Christoph Hellwig
2012-01-12 17:39 ` Ben Myers [this message]
2012-01-13 2:41 ` Jeff Liu
2012-01-11 15:43 ` Ben Myers
2012-01-11 22:28 ` Ben Myers
2012-01-12 13:21 ` Jeff Liu
2012-01-12 12:53 ` Jeff Liu
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=20120112173959.GU20739@sgi.com \
--to=bpm@sgi.com \
--cc=chris.mason@oracle.com \
--cc=hch@infradead.org \
--cc=jeff.liu@oracle.com \
--cc=tinguely@sgi.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