From: Christoph Hellwig <hch@infradead.org>
To: Mark Tinguely <tinguely@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>,
jeff.liu@oracle.com, Ben Myers <bpm@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 11:41:48 -0500 [thread overview]
Message-ID: <20120112164148.GB22223@infradead.org> (raw)
In-Reply-To: <4F0EF5DC.1070207@sgi.com>
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
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 16:41 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 [this message]
2012-01-12 17:39 ` Ben Myers
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=20120112164148.GB22223@infradead.org \
--to=hch@infradead.org \
--cc=bpm@sgi.com \
--cc=chris.mason@oracle.com \
--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