Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264643AbTE1KMh (ORCPT ); Wed, 28 May 2003 06:12:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264650AbTE1KMh (ORCPT ); Wed, 28 May 2003 06:12:37 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:14556 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S264643AbTE1KMd (ORCPT ); Wed, 28 May 2003 06:12:33 -0400 Date: Wed, 28 May 2003 12:25:29 +0200 From: Jens Axboe To: Andrew Morton Cc: Matthias Mueller , m.c.p@wolk-project.de, kernel@kolivas.org, manish@storadinc.com, andrea@suse.de, marcelo@conectiva.com.br, linux-kernel@vger.kernel.org Subject: Re: 2.4.20: Proccess stuck in __lock_page ... Message-ID: <20030528102529.GQ845@suse.de> References: <3ED2DE86.2070406@storadinc.com> <200305281713.24357.kernel@kolivas.org> <20030528071355.GO845@suse.de> <200305280930.48810.m.c.p@wolk-project.de> <20030528073544.GR845@suse.de> <20030528005156.1fda5710.akpm@digeo.com> <20030528101348.GA804@rz.uni-karlsruhe.de> <20030528032315.679e77b0.akpm@digeo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030528032315.679e77b0.akpm@digeo.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2777 Lines: 76 On Wed, May 28 2003, Andrew Morton wrote: > Matthias Mueller wrote: > > > > Works fine on my notebook. Good throughput and no mouse hangs anymore. > > Interesting. > > Could you please work out which change caused it? Go back to stock 2.4 and > then apply this: > > > diff -puN drivers/block/ll_rw_blk.c~1 drivers/block/ll_rw_blk.c > --- 24/drivers/block/ll_rw_blk.c~1 2003-05-28 03:20:42.000000000 -0700 > +++ 24-akpm/drivers/block/ll_rw_blk.c 2003-05-28 03:20:57.000000000 -0700 > @@ -590,10 +590,10 @@ static struct request *__get_request_wai > register struct request *rq; > DECLARE_WAITQUEUE(wait, current); > > - generic_unplug_device(q); > add_wait_queue_exclusive(&q->wait_for_requests[rw], &wait); > do { > set_current_state(TASK_UNINTERRUPTIBLE); > + generic_unplug_device(q); > if (q->rq[rw].count == 0) > schedule(); > spin_lock_irq(&io_request_lock); I think it was already established that this wasn't the reason. Was my first suspect too, though... > then this: > > diff -puN drivers/block/ll_rw_blk.c~2 drivers/block/ll_rw_blk.c > --- 24/drivers/block/ll_rw_blk.c~2 2003-05-28 03:21:03.000000000 -0700 > +++ 24-akpm/drivers/block/ll_rw_blk.c 2003-05-28 03:21:09.000000000 -0700 > @@ -590,7 +590,7 @@ static struct request *__get_request_wai > register struct request *rq; > DECLARE_WAITQUEUE(wait, current); > > - add_wait_queue_exclusive(&q->wait_for_requests[rw], &wait); > + add_wait_queue(&q->wait_for_requests[rw], &wait); > do { > set_current_state(TASK_UNINTERRUPTIBLE); > generic_unplug_device(q); Since we do a general wake_up(), only the order of wakeups matter here right (lifo vs fifo). Given that, the _exclusive() should be more fair possibly at the cost of a bit of throughput. > Then this (totally unlikely, don't bother): > > diff -puN drivers/block/ll_rw_blk.c~3 drivers/block/ll_rw_blk.c > --- 24/drivers/block/ll_rw_blk.c~3 2003-05-28 03:21:15.000000000 -0700 > +++ 24-akpm/drivers/block/ll_rw_blk.c 2003-05-28 03:21:39.000000000 -0700 > @@ -829,8 +829,7 @@ void blkdev_release_request(struct reque > */ > if (q) { > list_add(&req->queue, &q->rq[rw].free); > - if (++q->rq[rw].count >= q->batch_requests && > - waitqueue_active(&q->wait_for_requests[rw])) > + if (++q->rq[rw].count >= q->batch_requests) > wake_up(&q->wait_for_requests[rw]); > } > } Well it's the only one left :). But you are right, try one of them at the time, establishing the effect of each of them. -- Jens Axboe - 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/