Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270745AbTGNT4I (ORCPT ); Mon, 14 Jul 2003 15:56:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270755AbTGNT4H (ORCPT ); Mon, 14 Jul 2003 15:56:07 -0400 Received: from 69-55-72-150.ppp.netsville.net ([69.55.72.150]:20434 "EHLO tiny.suse.com") by vger.kernel.org with ESMTP id S270745AbTGNTzs (ORCPT ); Mon, 14 Jul 2003 15:55:48 -0400 Subject: Re: RFC on io-stalls patch From: Chris Mason To: Jens Axboe Cc: Marcelo Tosatti , Andrea Arcangeli , lkml , "Stephen C. Tweedie" , Alan Cox , Jeff Garzik , Andrew Morton , Alexander Viro In-Reply-To: <20030714195138.GX833@suse.de> References: <20030710135747.GT825@suse.de> <1057932804.13313.58.camel@tiny.suse.com> <20030712073710.GK843@suse.de> <1058034751.13318.95.camel@tiny.suse.com> <20030713090116.GU843@suse.de> <20030713191921.GI16313@dualathlon.random> <20030714054918.GD843@suse.de> <20030714131206.GJ833@suse.de> <20030714195138.GX833@suse.de> Content-Type: text/plain Organization: Message-Id: <1058213348.13313.274.camel@tiny.suse.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 Date: 14 Jul 2003 16:09:08 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1532 Lines: 43 On Mon, 2003-07-14 at 15:51, Jens Axboe wrote: > Some initial results with the attached patch, I'll try and do some more > fine grained tomorrow. Base kernel was 2.4.22-pre5 (obviously), drive > tested is a SCSI drive (on aic7xxx, tcq fixed at 4), fs is ext3. I would > have done ide testing actually, but the drive in that machine appears to > have gone dead. I'll pop in a new one tomorrow and test on that too. > Thanks Jens, the results so far are very interesting (although I'm curious to hear how 2.4.21 did). > --- 1.47/drivers/block/ll_rw_blk.c Fri Jul 11 10:30:54 2003 > +++ edited/drivers/block/ll_rw_blk.c Mon Jul 14 20:42:36 2003 > @@ -549,10 +549,12 @@ > static struct request *get_request(request_queue_t *q, int rw) > { > struct request *rq = NULL; > - struct request_list *rl; > + struct request_list *rl = &q->rq; > > - rl = &q->rq; > - if (!list_empty(&rl->free) && !blk_oversized_queue(q)) { > + if ((rw == WRITE) && (blk_oversized_queue(q) || (rl->count < 4))) > + return NULL; > + > + if (!list_empty(&rl->free)) { > rq = blkdev_free_rq(&rl->free); > list_del(&rq->queue); > rl->count--; > @@ -947,7 +949,7 @@ Could I talk you into trying a form of this patch that honors blk_oversized_queue for everything except the BH_sync requests? -chris - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/