From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752182Ab3FDWlI (ORCPT ); Tue, 4 Jun 2013 18:41:08 -0400 Received: from 1wt.eu ([62.212.114.60]:35138 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751751Ab3FDWkm (ORCPT ); Tue, 4 Jun 2013 18:40:42 -0400 Message-Id: <20130604172130.389042968@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 04 Jun 2013 19:21:32 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jens Axboe , Thomas Bork , Willy Tarreau Subject: [ 002/184] Revert "block: improve queue_should_plug() by In-Reply-To: <58df134a4b98edf5b0073e2e1e988fe6@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ looking at IO depths" From: Jens Axboe This reverts commit fb1e75389bd06fd5987e9cda1b4e0305c782f854. "Benjamin S." reports that the patch in question causes a big drop in sequential throughput for him, dropping from 200MB/sec down to only 70MB/sec. Needs to be investigated more fully, for now lets just revert the offending commit. Conflicts: include/linux/blkdev.h Signed-off-by: Jens Axboe (cherry picked from commit 79da0644a8e0838522828f106e4049639eea6baf) Cc: Thomas Bork Signed-off-by: Willy Tarreau --- block/blk-core.c | 11 ++--------- include/linux/blkdev.h | 4 +--- 2 files changed, 3 insertions(+), 12 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index cffd737..00ac586 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1149,7 +1149,7 @@ void init_request_from_bio(struct request *req, struct bio *bio) */ static inline bool queue_should_plug(struct request_queue *q) { - return !(blk_queue_nonrot(q) && blk_queue_queuing(q)); + return !(blk_queue_nonrot(q) && blk_queue_tagged(q)); } static int __make_request(struct request_queue *q, struct bio *bio) @@ -1861,15 +1861,8 @@ void blk_dequeue_request(struct request *rq) * and to it is freed is accounted as io that is in progress at * the driver side. */ - if (blk_account_rq(rq)) { + if (blk_account_rq(rq)) q->in_flight[rq_is_sync(rq)]++; - /* - * Mark this device as supporting hardware queuing, if - * we have more IOs in flight than 4. - */ - if (!blk_queue_queuing(q) && queue_in_flight(q) > 4) - set_bit(QUEUE_FLAG_CQ, &q->queue_flags); - } } /** diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5eb6cb0..ec9c10b 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -456,8 +456,7 @@ struct request_queue #define QUEUE_FLAG_NONROT 14 /* non-rotational device (SSD) */ #define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */ #define QUEUE_FLAG_IO_STAT 15 /* do IO stats */ -#define QUEUE_FLAG_CQ 16 /* hardware does queuing */ -#define QUEUE_FLAG_DISCARD 17 /* supports DISCARD */ +#define QUEUE_FLAG_DISCARD 16 /* supports DISCARD */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ @@ -580,7 +579,6 @@ enum { #define blk_queue_plugged(q) test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags) #define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags) -#define blk_queue_queuing(q) test_bit(QUEUE_FLAG_CQ, &(q)->queue_flags) #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) #define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags) -- 1.7.12.2.21.g234cd45.dirty