From patchwork Tue Aug 11 09:32:41 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikanth Karthikesan X-Patchwork-Id: 40551 Received: from hormel.redhat.com (hormel1.redhat.com [209.132.177.33]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n7B9VW22006113 for ; Tue, 11 Aug 2009 09:31:32 GMT Received: from listman.util.phx.redhat.com (listman.util.phx.redhat.com [10.8.4.110]) by hormel.redhat.com (Postfix) with ESMTP id AAD24619C65; Tue, 11 Aug 2009 05:31:31 -0400 (EDT) Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by listman.util.phx.redhat.com (8.13.1/8.13.1) with ESMTP id n7B9VQu8023340 for ; Tue, 11 Aug 2009 05:31:26 -0400 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n7B9VQF2021008; Tue, 11 Aug 2009 05:31:26 -0400 Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id n7B9VBBp004885; Tue, 11 Aug 2009 05:31:11 -0400 Received: from relay2.suse.de (relay-ext.suse.de [195.135.221.8]) by mx2.suse.de (Postfix) with ESMTP id E11F48726A; Tue, 11 Aug 2009 11:31:10 +0200 (CEST) From: Nikanth Karthikesan Organization: suse.de To: Kiyoshi Ueda Date: Tue, 11 Aug 2009 15:02:41 +0530 User-Agent: KMail/1.11.1 (Linux/2.6.27.23-0.1-default; KDE/4.2.1; x86_64; ; ) References: <200908081026.01097.knikanth@suse.de> <4A812680.7040804@ct.jp.nec.com> <200908111435.12020.knikanth@suse.de> In-Reply-To: <200908111435.12020.knikanth@suse.de> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200908111502.41930.knikanth@suse.de> X-RedHat-Spam-Score: -3.736 X-Scanned-By: MIMEDefang 2.58 on 172.16.52.254 X-Scanned-By: MIMEDefang 2.63 on 172.16.48.32 X-loop: dm-devel@redhat.com Cc: Mike Snitzer , linux-kernel@vger.kernel.org, dm-devel@redhat.com, Jens Axboe , Alasdair G Kergon Subject: [dm-devel] [PATCH-v3 2/2] Initialize mempool and elevator only for request-based dm devices X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.5 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com Intialize the request_queue and elevator only when the device is marked as a request-based device. This avoids unnecessary creation of mempool for requests. Also we wrongly initialize the elevator even for bio-based devices. As the /sys/block/dm-*/queue/scheduler is exported for device-mapper devices, it is possible to confuse with scheduler options for bio-based devices where scheduler is not at all used. Signed-off-by: Nikanth Karthikesan --- -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 8a311ea..40156b0 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1749,22 +1749,21 @@ static struct mapped_device *alloc_dev(int minor) INIT_LIST_HEAD(&md->uevent_list); spin_lock_init(&md->uevent_lock); - md->queue = blk_init_queue(dm_request_fn, NULL); + md->queue = blk_alloc_queue(GFP_KERNEL); if (!md->queue) goto bad_queue; /* * Request-based dm devices cannot be stacked on top of bio-based dm - * devices. The type of this dm device has not been decided yet, - * although we initialized the queue using blk_init_queue(). + * devices. The type of this dm device has not been decided yet. * The type is decided at the first table loading time. * To prevent problematic device stacking, clear the queue flag * for request stacking support until then. * * This queue is new, so no concurrency on the queue_flags. */ + md->queue->queue_flags = QUEUE_FLAG_DEFAULT; queue_flag_clear_unlocked(QUEUE_FLAG_STACKABLE, md->queue); - md->saved_make_request_fn = md->queue->make_request_fn; md->queue->queuedata = md; md->queue->backing_dev_info.congested_fn = dm_any_congested; md->queue->backing_dev_info.congested_data = md; @@ -1772,9 +1771,6 @@ static struct mapped_device *alloc_dev(int minor) blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY); md->queue->unplug_fn = dm_unplug_all; blk_queue_merge_bvec(md->queue, dm_merge_bvec); - blk_queue_softirq_done(md->queue, dm_softirq_done); - blk_queue_prep_rq(md->queue, dm_prep_fn); - blk_queue_lld_busy(md->queue, dm_lld_busy); md->disk = alloc_disk(1); if (!md->disk) @@ -2203,6 +2199,33 @@ int dm_swap_table(struct mapped_device *md, struct dm_table *table) goto out; } + /* new device is being marked as request-based */ + if (!md->map && dm_table_request_based(table)) { + /* + * Initialize queue for request-based dm. + * Generally DM must not allocate memory during resume as it + * may cause deadlock during no memory situation. But there is + * no I/O happening on this device. So it is ok to allocate + * memory here. + */ + r = blk_init_allocated_queue(md->queue, dm_request_fn, NULL); + if (r) + goto out; + + elv_register_queue(md->queue); + + /* + * reinitialize make_request_fn as it was reset to the + * default __make_request by blk_init_allocate_queue + */ + md->saved_make_request_fn = md->queue->make_request_fn; + blk_queue_make_request(md->queue, dm_request); + + blk_queue_softirq_done(md->queue, dm_softirq_done); + blk_queue_prep_rq(md->queue, dm_prep_fn); + blk_queue_lld_busy(md->queue, dm_lld_busy); + } + __unbind(md); r = __bind(md, table, &limits);