From: "hch@infradead.org" <hch@infradead.org>
To: NeilBrown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>,
Jens Axboe <jaxboe@fusionio.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"hch@infradead.org" <hch@infradead.org>,
dm-devel@redhat.com, linux-raid@vger.kernel.org
Subject: Re: [PATCH 05/10] block: remove per-queue plugging
Date: Mon, 11 Apr 2011 12:59:23 -0400 [thread overview]
Message-ID: <20110411165923.GA15442@infradead.org> (raw)
In-Reply-To: <20110411145022.710c30e9@notabene.brown>
On Mon, Apr 11, 2011 at 02:50:22PM +1000, NeilBrown wrote:
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 273d60b..903ce8d 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -2674,19 +2674,23 @@ static void flush_plug_list(struct blk_plug *plug)
> struct request_queue *q;
> unsigned long flags;
> struct request *rq;
> + struct list_head head;
>
> BUG_ON(plug->magic != PLUG_MAGIC);
>
> if (list_empty(&plug->list))
> return;
> + list_add(&head, &plug->list);
> + list_del_init(&plug->list);
>
> if (plug->should_sort)
> - list_sort(NULL, &plug->list, plug_rq_cmp);
> + list_sort(NULL, &head, plug_rq_cmp);
> + plug->should_sort = 0;
As Jens mentioned this should be list_splice_init. But looking over
flush_plug_list the code there seems strange to me.
What does the local_irq_save in flush_plug_list protect? Why don't
we need it over the list_sort? And do we still need it when first
splicing the list to a local one?
It's one of these cases where I'd really like to see more comments
explaining why the code is doing what it's doing.
next prev parent reply other threads:[~2011-04-11 16:59 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-22 1:17 [PATCH 0/10] On-stack explicit block queue plugging Jens Axboe
2011-01-22 1:17 ` [PATCH 01/10] block: add API for delaying work/request_fn a little bit Jens Axboe
2011-01-22 1:17 ` [PATCH 02/10] ide-cd: convert to blk_delay_queue() for a short pause Jens Axboe
2011-01-22 1:19 ` David Miller
2011-01-22 1:17 ` [PATCH 03/10] scsi: convert to blk_delay_queue() Jens Axboe
2011-01-22 1:17 ` [PATCH 04/10] block: initial patch for on-stack per-task plugging Jens Axboe
2011-01-24 19:36 ` Jeff Moyer
2011-01-24 21:23 ` Jens Axboe
2011-03-10 16:54 ` Vivek Goyal
2011-03-10 19:32 ` Jens Axboe
2011-03-10 19:46 ` Vivek Goyal
2011-03-16 8:18 ` Shaohua Li
2011-03-16 17:31 ` Vivek Goyal
2011-03-17 1:00 ` Shaohua Li
2011-03-17 3:19 ` Shaohua Li
2011-03-17 9:44 ` Jens Axboe
2011-03-18 1:55 ` Shaohua Li
2011-03-17 9:43 ` Jens Axboe
2011-03-18 6:36 ` Shaohua Li
2011-03-18 12:54 ` Jens Axboe
2011-03-18 13:52 ` Jens Axboe
2011-03-21 6:52 ` Shaohua Li
2011-03-21 9:20 ` Jens Axboe
2011-03-22 0:32 ` Shaohua Li
2011-03-22 7:36 ` Jens Axboe
2011-03-17 9:39 ` Jens Axboe
2011-01-22 1:17 ` [PATCH 05/10] block: remove per-queue plugging Jens Axboe
2011-01-22 1:31 ` Nick Piggin
2011-03-03 21:23 ` Mike Snitzer
2011-03-03 21:27 ` Mike Snitzer
2011-03-03 22:13 ` Mike Snitzer
2011-03-04 13:02 ` Shaohua Li
2011-03-04 13:20 ` Jens Axboe
2011-03-04 21:43 ` Mike Snitzer
2011-03-04 21:50 ` Jens Axboe
2011-03-04 22:27 ` Mike Snitzer
2011-03-05 20:54 ` Jens Axboe
2011-03-07 10:23 ` Peter Zijlstra
2011-03-07 19:43 ` Jens Axboe
2011-03-07 20:41 ` Peter Zijlstra
2011-03-07 20:46 ` Jens Axboe
2011-03-08 9:38 ` Peter Zijlstra
2011-03-08 9:41 ` Jens Axboe
2011-03-07 0:54 ` Shaohua Li
2011-03-07 8:07 ` Jens Axboe
2011-03-08 12:16 ` Jens Axboe
2011-03-08 20:21 ` Mike Snitzer
2011-03-08 20:27 ` Jens Axboe
2011-03-08 21:36 ` Jeff Moyer
2011-03-09 7:25 ` Jens Axboe
2011-03-08 22:05 ` Mike Snitzer
2011-03-10 0:58 ` Mike Snitzer
2011-04-05 3:05 ` NeilBrown
2011-04-11 4:50 ` NeilBrown
2011-04-11 9:19 ` Jens Axboe
2011-04-11 10:59 ` NeilBrown
2011-04-11 11:04 ` Jens Axboe
2011-04-11 11:26 ` NeilBrown
2011-04-11 11:37 ` Jens Axboe
2011-04-11 12:05 ` NeilBrown
2011-04-11 12:11 ` Jens Axboe
2011-04-11 12:36 ` NeilBrown
2011-04-11 12:48 ` Jens Axboe
2011-04-12 1:12 ` hch
2011-04-12 8:36 ` Jens Axboe
2011-04-12 12:22 ` Dave Chinner
2011-04-12 12:28 ` Jens Axboe
2011-04-12 12:41 ` Dave Chinner
2011-04-12 12:58 ` Jens Axboe
2011-04-12 13:31 ` Dave Chinner
2011-04-12 13:45 ` Jens Axboe
2011-04-12 14:34 ` Dave Chinner
2011-04-12 21:08 ` NeilBrown
2011-04-13 2:23 ` Linus Torvalds
2011-04-13 11:12 ` Peter Zijlstra
2011-04-13 11:23 ` Jens Axboe
2011-04-13 11:41 ` Peter Zijlstra
2011-04-13 15:13 ` Linus Torvalds
2011-04-13 17:35 ` Jens Axboe
2011-04-12 16:58 ` hch
2011-04-12 17:29 ` Jens Axboe
2011-04-12 16:44 ` hch
2011-04-12 16:49 ` Jens Axboe
2011-04-12 16:54 ` hch
2011-04-12 17:24 ` Jens Axboe
2011-04-12 13:40 ` Dave Chinner
2011-04-12 13:48 ` Jens Axboe
2011-04-12 23:35 ` Dave Chinner
2011-04-12 16:50 ` hch
2011-04-15 4:26 ` hch
2011-04-15 6:34 ` Jens Axboe
2011-04-17 22:19 ` NeilBrown
2011-04-18 4:19 ` NeilBrown
2011-04-18 6:38 ` Jens Axboe
2011-04-18 7:25 ` NeilBrown
2011-04-18 8:10 ` Jens Axboe
2011-04-18 8:33 ` NeilBrown
2011-04-18 8:42 ` Jens Axboe
2011-04-18 21:23 ` hch
2011-04-22 15:39 ` hch
2011-04-22 16:01 ` Vivek Goyal
2011-04-22 16:10 ` Vivek Goyal
2011-04-18 21:30 ` hch
2011-04-18 22:38 ` NeilBrown
2011-04-20 10:55 ` hch
2011-04-18 9:19 ` hch
2011-04-18 9:40 ` [dm-devel] " Hannes Reinecke
2011-04-18 9:47 ` Jens Axboe
2011-04-18 9:46 ` Jens Axboe
2011-04-11 11:55 ` NeilBrown
2011-04-11 12:12 ` Jens Axboe
2011-04-11 22:58 ` hch
2011-04-12 6:20 ` Jens Axboe
2011-04-11 16:59 ` hch [this message]
2011-04-11 21:14 ` NeilBrown
2011-04-11 22:59 ` hch
2011-04-12 6:18 ` Jens Axboe
2011-03-17 15:51 ` Mike Snitzer
2011-03-17 18:31 ` Jens Axboe
2011-03-17 18:46 ` Mike Snitzer
2011-03-18 9:15 ` hch
2011-03-08 12:15 ` Jens Axboe
2011-03-04 4:00 ` Vivek Goyal
2011-03-08 12:24 ` Jens Axboe
2011-03-08 22:10 ` blk-throttle: Use blk_plug in throttle code (Was: Re: [PATCH 05/10] block: remove per-queue plugging) Vivek Goyal
2011-03-09 7:26 ` Jens Axboe
2011-01-22 1:17 ` [PATCH 06/10] block: kill request allocation batching Jens Axboe
2011-01-22 9:31 ` Christoph Hellwig
2011-01-24 19:09 ` Jens Axboe
2011-01-22 1:17 ` [PATCH 07/10] fs: make generic file read/write functions plug Jens Axboe
2011-01-24 3:57 ` Dave Chinner
2011-01-24 19:11 ` Jens Axboe
2011-03-04 4:09 ` Vivek Goyal
2011-03-04 13:22 ` Jens Axboe
2011-03-04 13:25 ` hch
2011-03-04 13:40 ` Jens Axboe
2011-03-04 14:08 ` hch
2011-03-04 22:07 ` Jens Axboe
2011-03-04 23:12 ` hch
2011-03-08 12:38 ` Jens Axboe
2011-03-09 10:38 ` hch
2011-03-09 10:52 ` Jens Axboe
2011-01-22 1:17 ` [PATCH 08/10] read-ahead: use plugging Jens Axboe
2011-01-22 1:17 ` [PATCH 09/10] fs: make mpage read/write_pages() plug Jens Axboe
2011-01-22 1:17 ` [PATCH 10/10] fs: make aio plug Jens Axboe
2011-01-24 17:59 ` Jeff Moyer
2011-01-24 19:09 ` Jens Axboe
2011-01-24 19:15 ` Jeff Moyer
2011-01-24 19:22 ` Jens Axboe
2011-01-24 19:29 ` Jeff Moyer
2011-01-24 19:31 ` Jens Axboe
2011-01-24 19:38 ` Jeff Moyer
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=20110411165923.GA15442@infradead.org \
--to=hch@infradead.org \
--cc=dm-devel@redhat.com \
--cc=jaxboe@fusionio.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
--cc=neilb@suse.de \
--cc=snitzer@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).