From: Shaohua Li <shaohua.li@intel.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: [patch 1/2]block: avoid unnecessary plug list flush
Date: Wed, 28 Sep 2011 11:11:25 +0800 [thread overview]
Message-ID: <1317179485.22361.10.camel@sli10-conroe> (raw)
get_request_wait() could sleep and flush the plug list. If the list
is already flushed, don't flush again.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---
block/blk-core.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
Index: linux/block/blk-core.c
===================================================================
--- linux.orig/block/blk-core.c 2011-09-28 11:05:06.000000000 +0800
+++ linux/block/blk-core.c 2011-09-28 11:05:22.000000000 +0800
@@ -1299,15 +1299,17 @@ get_rq:
*/
if (list_empty(&plug->list))
trace_block_plug(q);
- else if (!plug->should_sort) {
- struct request *__rq;
+ else {
+ if (!plug->should_sort) {
+ struct request *__rq;
- __rq = list_entry_rq(plug->list.prev);
- if (__rq->q != q)
- plug->should_sort = 1;
+ __rq = list_entry_rq(plug->list.prev);
+ if (__rq->q != q)
+ plug->should_sort = 1;
+ }
+ if (request_count >= BLK_MAX_REQUEST_COUNT)
+ blk_flush_plug_list(plug, false);
}
- if (request_count >= BLK_MAX_REQUEST_COUNT)
- blk_flush_plug_list(plug, false);
list_add_tail(&req->queuelist, &plug->list);
drive_stat_acct(req, 1);
} else {
next reply other threads:[~2011-09-28 3:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-28 3:11 Shaohua Li [this message]
2011-09-28 8:47 ` Namhyung Kim
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=1317179485.22361.10.camel@sli10-conroe \
--to=shaohua.li@intel.com \
--cc=axboe@kernel.dk \
--cc=linux-kernel@vger.kernel.org \
/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
all inboxes | Powered by JetHome®