From: Matthew Wilcox <willy@infradead.org>
To: Ming Lei <ming.lei@redhat.com>
Cc: Ming Lei <tom.leiming@gmail.com>,
Vlastimil Babka <vbabka@suse.cz>,
Dave Chinner <david@fromorbit.com>,
"Darrick J . Wong" <darrick.wong@oracle.com>,
"open list:XFS FILESYSTEM" <linux-xfs@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Dave Chinner <dchinner@redhat.com>,
Christoph Hellwig <hch@lst.de>,
Alexander Duyck <alexander.h.duyck@linux.intel.com>,
Aaron Lu <aaron.lu@intel.com>, Christopher Lameter <cl@linux.com>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
linux-mm <linux-mm@kvack.org>,
linux-block <linux-block@vger.kernel.org>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH] xfs: allocate sector sized IO buffer via page_frag_alloc
Date: Tue, 26 Feb 2019 05:02:30 -0800 [thread overview]
Message-ID: <20190226130230.GD11592@bombadil.infradead.org> (raw)
In-Reply-To: <20190226123545.GA6163@ming.t460p>
On Tue, Feb 26, 2019 at 08:35:46PM +0800, Ming Lei wrote:
> On Tue, Feb 26, 2019 at 04:12:09AM -0800, Matthew Wilcox wrote:
> > On Tue, Feb 26, 2019 at 07:12:49PM +0800, Ming Lei wrote:
> > > The buffer needs to be device block size aligned for dio, and now the block
> > > size can be 512, 1024, 2048 and 4096.
> >
> > Why does the block size make a difference? This requirement is due to
> > some storage devices having shoddy DMA controllers. Are you saying there
> > are devices which can't even do 512-byte aligned I/O?
>
> Direct IO requires that, see do_blockdev_direct_IO().
>
> This issue can be triggered when running xfs over loop/dio. We could
> fallback to buffered IO under this situation, but not sure it is the
> only case.
Wait, we're imposing a ridiculous amount of complexity on XFS for no
reason at all? We should just change this to 512-byte alignment. Tying
it to the blocksize of the device never made any sense.
next prev parent reply other threads:[~2019-02-26 13:02 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-25 4:09 [PATCH] xfs: allocate sector sized IO buffer via page_frag_alloc Ming Lei
2019-02-25 4:36 ` Dave Chinner
2019-02-25 8:46 ` Ming Lei
2019-02-25 10:03 ` Ming Lei
2019-02-25 20:11 ` Dave Chinner
2019-02-25 13:15 ` Vlastimil Babka
2019-02-25 20:26 ` Dave Chinner
2019-02-26 2:22 ` Ming Lei
2019-02-26 3:02 ` Dave Chinner
2019-02-26 3:27 ` Matthew Wilcox
2019-02-26 4:58 ` Dave Chinner
2019-02-26 9:33 ` Ming Lei
2019-02-26 10:06 ` Vlastimil Babka
2019-02-26 11:12 ` Ming Lei
2019-02-26 12:12 ` Matthew Wilcox
2019-02-26 12:35 ` Ming Lei
2019-02-26 13:02 ` Matthew Wilcox [this message]
2019-02-26 13:42 ` Ming Lei
2019-02-26 14:04 ` Matthew Wilcox
2019-02-26 16:14 ` Darrick J. Wong
2019-02-26 16:19 ` Matthew Wilcox
2019-02-27 1:41 ` Ming Lei
2019-02-27 7:07 ` Vlastimil Babka
2019-03-08 8:18 ` Christoph Hellwig
2019-02-27 21:38 ` Dave Chinner
2019-02-26 15:30 ` Christopher Lameter
2019-02-26 20:45 ` Dave Chinner
2019-02-27 1:50 ` Ming Lei
2019-02-27 3:41 ` Dave Chinner
2019-02-26 15:20 ` Christopher Lameter
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=20190226130230.GD11592@bombadil.infradead.org \
--to=willy@infradead.org \
--cc=aaron.lu@intel.com \
--cc=alexander.h.duyck@linux.intel.com \
--cc=axboe@kernel.dk \
--cc=cl@linux.com \
--cc=darrick.wong@oracle.com \
--cc=david@fromorbit.com \
--cc=dchinner@redhat.com \
--cc=hch@lst.de \
--cc=iamjoonsoo.kim@lge.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-xfs@vger.kernel.org \
--cc=ming.lei@redhat.com \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
--cc=tom.leiming@gmail.com \
--cc=vbabka@suse.cz \
--cc=vkuznets@redhat.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;
as well as URLs for NNTP newsgroup(s).