linux-kernel - [PATCH]cfq-iosched: removing unnecessary think time checking

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1300157851.2337.78.camel@sli10-conroe>
Date:	Tue, 15 Mar 2011 10:57:31 +0800
From:	Shaohua Li <shaohua.li@...el.com>
To:	Jens Axboe <jaxboe@...ionio.com>
Cc:	lkml <linux-kernel@...r.kernel.org>,
	Vivek Goyal <vgoyal@...hat.com>,
	Jeff Moyer <jmoyer@...hat.com>,
	Corrado Zoccolo <czoccolo@...il.com>,
	Gui Jianfeng <guijianfeng@...fujitsu.com>
Subject: [PATCH]cfq-iosched: removing unnecessary think time checking

Removing think time checking. A high thinktime queue might means the queue
dispatches several requests and then do away. Limitting such queue seems
meaningless. And also this can simplify code. This is suggested by Vivek.

Signed-off-by: Shaohua Li <shaohua.li@...el.com>

---
 block/cfq-iosched.c |   13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

Index: linux/block/cfq-iosched.c
===================================================================
--- linux.orig/block/cfq-iosched.c	2011-03-10 13:52:13.000000000 +0800
+++ linux/block/cfq-iosched.c	2011-03-10 13:53:08.000000000 +0800
@@ -2418,19 +2418,14 @@ static bool cfq_may_dispatch(struct cfq_
 			return false;
 
 		/*
-		 * If there is only one sync queue, and its think time is
-		 * small, we can ignore async queue here and give the sync
+		 * If there is only one sync queue
+		 * we can ignore async queue here and give the sync
 		 * queue no dispatch limit. The reason is a sync queue can
 		 * preempt async queue, limiting the sync queue doesn't make
 		 * sense. This is useful for aiostress test.
 		 */
-		if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) {
-			struct cfq_io_context *cic = RQ_CIC(cfqq->next_rq);
-
-			if (sample_valid(cic->ttime_samples) &&
-				cic->ttime_mean < cfqd->cfq_slice_idle)
-				promote_sync = true;
-		}
+		if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1)
+			promote_sync = true;
 
 		/*
 		 * We have other queues, don't allow more IO from this one


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/