From patchwork Tue Jun 1 09:56:19 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 103484 X-Patchwork-Delegate: jbrassow@redhat.com Received: from mx01.colomx.prod.int.phx2.redhat.com (mx3-phx2.redhat.com [209.132.183.24]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o51C5vd1000516 for ; Tue, 1 Jun 2010 12:06:32 GMT Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by mx01.colomx.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o51C3ude006298; Tue, 1 Jun 2010 08:03:56 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o51A02el002356 for ; Tue, 1 Jun 2010 06:00:02 -0400 Received: from mx1.redhat.com (ext-mx09.extmail.prod.ext.phx2.redhat.com [10.5.110.13]) by int-mx04.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o519xvv0031205; Tue, 1 Jun 2010 05:59:57 -0400 Received: from mx1.suse.de (cantor.suse.de [195.135.220.2]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o519xkfo024140; Tue, 1 Jun 2010 05:59:47 -0400 Received: from relay2.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 A5C2F94608; Tue, 1 Jun 2010 11:59:46 +0200 (CEST) From: NeilBrown To: Heinz Mauelshagen , Alasdair G Kergon Date: Tue, 01 Jun 2010 19:56:19 +1000 Message-ID: <20100601095619.565.67150.stgit@notabene.brown> In-Reply-To: <20100601094414.565.3638.stgit@notabene.brown> References: <20100601094414.565.3638.stgit@notabene.brown> User-Agent: StGit/0.15 MIME-Version: 1.0 X-RedHat-Spam-Score: -5.01 (RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD) X-Scanned-By: MIMEDefang 2.67 on 10.5.11.17 X-Scanned-By: MIMEDefang 2.67 on 10.5.110.13 X-loop: dm-devel@redhat.com Cc: linux-raid@vger.kernel.org, dm-devel@redhat.com Subject: [dm-devel] [PATCH 11/24] md/raid5: add simple plugging infrastructure. 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-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 01 Jun 2010 12:06:33 +0000 (UTC) diff --git a/drivers/md/md.c b/drivers/md/md.c index da860f7..e44b9c6 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -384,6 +384,51 @@ void md_barrier_request(mddev_t *mddev, struct bio *bio) } EXPORT_SYMBOL(md_barrier_request); +/* Support for plugging. + * This mirrors the plugging support in request_queue, but does not + * require having a whole queue + */ +static void plugger_work(struct work_struct *work) +{ + struct plug_handle *plug = + container_of(work, struct plug_handle, unplug_work); + plug->unplug_fn(plug); +} +static void plugger_timeout(unsigned long data) +{ + struct plug_handle *plug = (void *)data; + kblockd_schedule_work(NULL, &plug->unplug_work); +} +void plugger_init(struct plug_handle *plug, + void (*unplug_fn)(struct plug_handle *)) +{ + plug->unplug_flag = 0; + plug->unplug_fn = unplug_fn; + init_timer(&plug->unplug_timer); + plug->unplug_timer.function = plugger_timeout; + plug->unplug_timer.data = (unsigned long)plug; + INIT_WORK(&plug->unplug_work, plugger_work); +} +EXPORT_SYMBOL_GPL(plugger_init); + +void plugger_set_plug(struct plug_handle *plug) +{ + if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag)) + mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1); +} +EXPORT_SYMBOL_GPL(plugger_set_plug); + +int plugger_remove_plug(struct plug_handle *plug) +{ + if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) { + del_timer(&plug->unplug_timer); + return 1; + } else + return 0; +} +EXPORT_SYMBOL_GPL(plugger_remove_plug); + + static inline mddev_t *mddev_get(mddev_t *mddev) { atomic_inc(&mddev->active); diff --git a/drivers/md/md.h b/drivers/md/md.h index 6318175..f210482 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -29,6 +29,26 @@ typedef struct mddev_s mddev_t; typedef struct mdk_rdev_s mdk_rdev_t; +/* generic plugging support - like that provided with request_queue, + * but does not require a request_queue + */ +struct plug_handle { + void (*unplug_fn)(struct plug_handle *); + struct timer_list unplug_timer; + struct work_struct unplug_work; + unsigned long unplug_flag; +}; +#define PLUGGED_FLAG 1 +void plugger_init(struct plug_handle *plug, + void (*unplug_fn)(struct plug_handle *)); +void plugger_set_plug(struct plug_handle *plug); +int plugger_remove_plug(struct plug_handle *plug); +static inline void plugger_flush(struct plug_handle *plug) +{ + del_timer_sync(&plug->unplug_timer); + cancel_work_sync(&plug->unplug_work); +} + /* * MD's 'extended' device */ diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c0746af..6b1802c 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -201,11 +201,11 @@ static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh) if (test_bit(STRIPE_HANDLE, &sh->state)) { if (test_bit(STRIPE_DELAYED, &sh->state)) { list_add_tail(&sh->lru, &conf->delayed_list); - blk_plug_device(conf->mddev->queue); + plugger_set_plug(&conf->plug); } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) && sh->bm_seq - conf->seq_write > 0) { list_add_tail(&sh->lru, &conf->bitmap_list); - blk_plug_device(conf->mddev->queue); + plugger_set_plug(&conf->plug); } else { clear_bit(STRIPE_BIT_DELAY, &sh->state); list_add_tail(&sh->lru, &conf->handle_list); @@ -365,7 +365,7 @@ static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector, } static void unplug_slaves(mddev_t *mddev); -static void raid5_unplug_device(struct request_queue *q); +static void raid5_unplug_device(raid5_conf_t *conf); static struct stripe_head * get_active_stripe(raid5_conf_t *conf, sector_t sector, @@ -395,7 +395,7 @@ get_active_stripe(raid5_conf_t *conf, sector_t sector, < (conf->max_nr_stripes *3/4) || !conf->inactive_blocked), conf->device_lock, - raid5_unplug_device(conf->mddev->queue) + raid5_unplug_device(conf) ); conf->inactive_blocked = 0; } else @@ -3532,7 +3532,7 @@ static void raid5_activate_delayed(raid5_conf_t *conf) list_add_tail(&sh->lru, &conf->hold_list); } } else - blk_plug_device(conf->mddev->queue); + plugger_set_plug(&conf->plug); } static void activate_bit_delay(raid5_conf_t *conf) @@ -3573,23 +3573,33 @@ static void unplug_slaves(mddev_t *mddev) rcu_read_unlock(); } -static void raid5_unplug_device(struct request_queue *q) +static void raid5_unplug_device(raid5_conf_t *conf) { - mddev_t *mddev = q->queuedata; - raid5_conf_t *conf = mddev->private; unsigned long flags; spin_lock_irqsave(&conf->device_lock, flags); - if (blk_remove_plug(q)) { + if (plugger_remove_plug(&conf->plug)) { conf->seq_flush++; raid5_activate_delayed(conf); } - md_wakeup_thread(mddev->thread); + md_wakeup_thread(conf->mddev->thread); spin_unlock_irqrestore(&conf->device_lock, flags); - unplug_slaves(mddev); + unplug_slaves(conf->mddev); +} + +static void raid5_unplug(struct plug_handle *plug) +{ + raid5_conf_t *conf = container_of(plug, raid5_conf_t, plug); + raid5_unplug_device(conf); +} + +static void raid5_unplug_queue(struct request_queue *q) +{ + mddev_t *mddev = q->queuedata; + raid5_unplug_device(mddev->private); } int md_raid5_congested(mddev_t *mddev, int bits) @@ -3999,7 +4009,7 @@ static int make_request(mddev_t *mddev, struct bio * bi) * add failed due to overlap. Flush everything * and wait a while */ - raid5_unplug_device(mddev->queue); + raid5_unplug_device(conf); release_stripe(sh); schedule(); goto retry; @@ -5089,6 +5099,7 @@ static int run(mddev_t *mddev) mdname(mddev)); md_set_array_sectors(mddev, raid5_size(mddev, 0, 0)); + plugger_init(&conf->plug, raid5_unplug); if (mddev->queue) { /* read-ahead size must cover two whole stripes, which * is 2 * (datadisks) * chunksize where 'n' is the @@ -5108,7 +5119,7 @@ static int run(mddev_t *mddev) mddev->queue->queue_lock = &conf->device_lock; - mddev->queue->unplug_fn = raid5_unplug_device; + mddev->queue->unplug_fn = raid5_unplug_queue; chunk_size = mddev->chunk_sectors << 9; blk_queue_io_min(mddev->queue, chunk_size); @@ -5140,7 +5151,7 @@ static int stop(mddev_t *mddev) mddev->thread = NULL; if (mddev->queue) mddev->queue->backing_dev_info.congested_fn = NULL; - blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ + plugger_flush(&conf->plug); /* the unplug fn references 'conf'*/ free_conf(conf); mddev->private = NULL; mddev->to_remove = &raid5_attrs_group; diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 936caf8..edf90a8 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -398,6 +398,9 @@ struct raid5_private_data { * (fresh device added). * Cleared when a sync completes. */ + + struct plug_handle plug; + /* per cpu variables */ struct raid5_percpu { struct page *spare_page; /* Used when checking P/Q in raid6 */