From: NeilBrown <neilb@suse.de>
To: Ming Lin <mlin@kernel.org>
Cc: linux-kernel@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Jens Axboe <axboe@kernel.dk>,
Kent Overstreet <kent.overstreet@gmail.com>,
Dongsu Park <dongsu.park@profitbricks.com>,
Lars Ellenberg <drbd-dev@lists.linbit.com>,
drbd-user@lists.linbit.com, Jiri Kosina <jkosina@suse.cz>,
Yehuda Sadeh <yehuda@inktank.com>, Sage Weil <sage@inktank.com>,
Alex Elder <elder@kernel.org>,
ceph-devel@vger.kernel.org, Alasdair Kergon <agk@redhat.com>,
Mike Snitzer <snitzer@redhat.com>,
dm-devel@redhat.com, linux-raid@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: [PATCH 07/10] block: kill merge_bvec_fn() completely
Date: Wed, 29 Apr 2015 08:09:19 +1000 [thread overview]
Message-ID: <20150429080919.342fddfd@notabene.brown> (raw)
In-Reply-To: <1430203717-13307-8-git-send-email-mlin@kernel.org>
[-- Attachment #1: Type: text/plain, Size: 723 bytes --]
On Mon, 27 Apr 2015 23:48:34 -0700 Ming Lin <mlin@kernel.org> wrote:
> From: Kent Overstreet <kent.overstreet@gmail.com>
>
> As generic_make_request() is now able to handle arbitrarily sized bios,
> it's no longer necessary for each individual block driver to define its
> own ->merge_bvec_fn() callback. Remove every invocation completely.
This patch it just a little premature I think.
md/raid5 still assumes read requests will mostly fit within a single chunk
(which merge_bvec_fn encourages) so they can be serviced without using the
stripe-cache.
You've just broken that assumption.
I think 'chunk_aligned_read' needs to get a loop using bio_split, a bit like
raid0, first.
Thanks,
NeilBrown
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 811 bytes --]
next prev parent reply other threads:[~2015-04-28 22:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1430203717-13307-1-git-send-email-mlin@kernel.org>
2015-04-28 6:48 ` [PATCH 06/10] md/raid5: get rid of bio_fits_rdev() Ming Lin
2015-04-28 6:48 ` [PATCH 07/10] block: kill merge_bvec_fn() completely Ming Lin
2015-04-28 17:31 ` Alasdair G Kergon
2015-04-29 6:32 ` Ming Lin
2015-04-28 22:09 ` NeilBrown [this message]
2015-05-04 7:47 ` Ming Lin
2015-05-06 7:10 ` Ming Lin
2015-05-06 7:26 ` Christoph Hellwig
2015-05-06 17:05 ` Ming Lin
2015-04-28 6:48 ` [PATCH 09/10] md/raid10: make sync_request_write() call bio_copy_data() Ming Lin
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=20150429080919.342fddfd@notabene.brown \
--to=neilb@suse.de \
--cc=agk@redhat.com \
--cc=axboe@kernel.dk \
--cc=ceph-devel@vger.kernel.org \
--cc=dm-devel@redhat.com \
--cc=dongsu.park@profitbricks.com \
--cc=drbd-dev@lists.linbit.com \
--cc=drbd-user@lists.linbit.com \
--cc=elder@kernel.org \
--cc=hch@infradead.org \
--cc=hch@lst.de \
--cc=jkosina@suse.cz \
--cc=kent.overstreet@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=mlin@kernel.org \
--cc=sage@inktank.com \
--cc=snitzer@redhat.com \
--cc=yehuda@inktank.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).