From patchwork Mon Apr 18 04:19:01 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 714231 Received: from mx4-phx2.redhat.com (mx4-phx2.redhat.com [209.132.183.25]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p3I4Lelo008248 for ; Mon, 18 Apr 2011 04:22:01 GMT Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by mx4-phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p3I4JPj9018928; Mon, 18 Apr 2011 00:19:27 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p3I4JNpH018247 for ; Mon, 18 Apr 2011 00:19:23 -0400 Received: from mx1.redhat.com (ext-mx14.extmail.prod.ext.phx2.redhat.com [10.5.110.19]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p3I4JHSN020960; Mon, 18 Apr 2011 00:19:18 -0400 Received: from mx1.suse.de (cantor.suse.de [195.135.220.2]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p3I4JDoV011472; Mon, 18 Apr 2011 00:19:14 -0400 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.221.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.suse.de (Postfix) with ESMTP id E08DC939FD; Mon, 18 Apr 2011 06:19:12 +0200 (CEST) Date: Mon, 18 Apr 2011 14:19:01 +1000 From: NeilBrown To: Jens Axboe Message-ID: <20110418141901.14e89cee@notabene.brown> In-Reply-To: <20110418081922.1651474a@notabene.brown> References: <1295659049-2688-1-git-send-email-jaxboe@fusionio.com> <1295659049-2688-6-git-send-email-jaxboe@fusionio.com> <20110303221353.GA10366@redhat.com> <4D761E0D.8050200@fusionio.com> <20110308202100.GA31744@redhat.com> <4D76912C.9040705@fusionio.com> <20110308220526.GA393@redhat.com> <20110310005810.GA17911@redhat.com> <20110405130541.6c2b5f86@notabene.brown> <20110411145022.710c30e9@notabene.brown> <4DA2C7BE.6060804@fusionio.com> <20110411205928.13915719@notabene.brown> <4DA2E03A.2080607@fusionio.com> <20110411212635.7959de70@notabene.brown> <4DA2E7F0.9010904@fusionio.com> <20110411220505.1028816e@notabene.brown> <4DA2F00E.6010907@fusionio.com> <20110418081922.1651474a@notabene.brown> Mime-Version: 1.0 X-RedHat-Spam-Score: -5.01 (RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD) X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Scanned-By: MIMEDefang 2.68 on 10.5.110.19 X-MIME-Autoconverted: from quoted-printable to 8bit by lists01.pubmisc.prod.ext.phx2.redhat.com id p3I4JNpH018247 X-loop: dm-devel@redhat.com Cc: "hch@infradead.org" , "linux-raid@vger.kernel.org" , "dm-devel@redhat.com" , "linux-kernel@vger.kernel.org" , Mike Snitzer Subject: Re: [dm-devel] [PATCH 05/10] block: remove per-queue plugging X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 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 X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Mon, 18 Apr 2011 04:22:10 +0000 (UTC) On Mon, 18 Apr 2011 08:19:22 +1000 NeilBrown wrote: > So can we please have my original patch applied? (Revised version using > list_splice_init included below). I hadn't adjusted that one properly for the recent code shuffling. This one is actually tested... Thanks, NeilBrown >From 325b1c12b6165002022bd7b599f95c0331491cb3 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 18 Apr 2011 14:06:05 +1000 Subject: [PATCH] Enhance new plugging support to support general callbacks. md/raid requires an unplug callback, but as it does not uses requests the current code cannot provide one. So allow arbitrary callbacks to be attached to the blk_plug. Cc: Jens Axboe Signed-off-by: NeilBrown --- block/blk-core.c | 20 ++++++++++++++++++++ include/linux/blkdev.h | 7 ++++++- 2 files changed, 26 insertions(+), 1 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 78b7b0c..77edf05 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2638,6 +2638,7 @@ void blk_start_plug(struct blk_plug *plug) plug->magic = PLUG_MAGIC; INIT_LIST_HEAD(&plug->list); + INIT_LIST_HEAD(&plug->cb_list); plug->should_sort = 0; /* @@ -2678,6 +2679,24 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth, q->unplugged_fn(q); } +static void flush_plug_callbacks(struct blk_plug *plug) +{ + LIST_HEAD(callbacks); + + if (list_empty(&plug->cb_list)) + return; + + list_splice_init(&plug->cb_list, &callbacks); + + while (!list_empty(&callbacks)) { + struct blk_plug_cb *cb = list_first_entry(&callbacks, + struct blk_plug_cb, + list); + list_del(&cb->list); + cb->callback(cb); + } +} + void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) { struct request_queue *q; @@ -2688,6 +2707,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) BUG_ON(plug->magic != PLUG_MAGIC); + flush_plug_callbacks(plug); if (list_empty(&plug->list)) return; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ec0357d..f3f7879 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -860,8 +860,13 @@ extern void blk_put_queue(struct request_queue *); struct blk_plug { unsigned long magic; struct list_head list; + struct list_head cb_list; unsigned int should_sort; }; +struct blk_plug_cb { + struct list_head list; + void (*callback)(struct blk_plug_cb *); +}; extern void blk_start_plug(struct blk_plug *); extern void blk_finish_plug(struct blk_plug *); @@ -887,7 +892,7 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk) { struct blk_plug *plug = tsk->plug; - return plug && !list_empty(&plug->list); + return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list)); } /*