From: Christoph Hellwig <hch@infradead.org>
To: Jan Kara <jack@suse.cz>
Cc: Ben Myers <bpm@sgi.com>, Alex Elder <elder@kernel.org>,
David Chinner <dchinner@redhat.com>,
xfs@oss.sgi.com
Subject: Re: [PATCH v2] xfs: Fix overallocation in xfs_buf_allocate_memory()
Date: Wed, 20 Jun 2012 02:39:01 -0400 [thread overview]
Message-ID: <20120620063901.GA14760@infradead.org> (raw)
In-Reply-To: <1338935546-3914-1-git-send-email-jack@suse.cz>
On Wed, Jun 06, 2012 at 12:32:26AM +0200, Jan Kara wrote:
> Commit de1cbee which removed b_file_offset in favor of b_bn introduced a bug
> causing xfs_buf_allocate_memory() to overestimate the number of necessary
> pages. The problem is that xfs_buf_alloc() sets b_bn to -1 and thus effectively
> every buffer is straddling a page boundary which causes
> xfs_buf_allocate_memory() to allocate two pages and use vmalloc() for access
> which is unnecessary.
>
> Dave says xfs_buf_alloc() doesn't need to set b_bn to -1 anymore since the
> buffer is inserted into the cache only after being fully initialized now.
> So just make xfs_buf_alloc() fill in proper block number from the beginning.
Looks good. The b_io_length initialization in xfs_buf_get can also be
removed, but as that's a cosmetic change it can way for 3.6.
Reviewed-by: Christoph Hellwig <hch@lst.de>
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2012-06-20 6:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-05 22:32 [PATCH v2] xfs: Fix overallocation in xfs_buf_allocate_memory() Jan Kara
2012-06-20 6:39 ` Christoph Hellwig [this message]
2012-06-20 6:41 ` 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=20120620063901.GA14760@infradead.org \
--to=hch@infradead.org \
--cc=bpm@sgi.com \
--cc=dchinner@redhat.com \
--cc=elder@kernel.org \
--cc=jack@suse.cz \
--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 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.