Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756961Ab2BAUwd (ORCPT ); Wed, 1 Feb 2012 15:52:33 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:33552 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932095Ab2BAUvF (ORCPT ); Wed, 1 Feb 2012 15:51:05 -0500 From: Tejun Heo To: axboe@kernel.dk, vgoyal@redhat.com Cc: ctalbott@google.com, rni@google.com, linux-kernel@vger.kernel.org, Tejun Heo Subject: [PATCH 12/16] blkcg: use the usual get blkg path for root blkio_group Date: Wed, 1 Feb 2012 12:50:25 -0800 Message-Id: <1328129429-11823-13-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: <1328129429-11823-1-git-send-email-tj@kernel.org> References: <1328129429-11823-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9148 Lines: 302 For root blkg, blk_throtl_init() was using throtl_alloc_tg() explicitly and cfq_init_queue() was manually initializing embedded cfqd->root_group, adding unnecessarily different code paths to blkg handling. Make both use the usual blkio_group get functions - throtl_get_tg() and cfq_get_cfqg() - for the root blkio_group too. Note that blk_throtl_init() callsite is pushed downwards in blk_alloc_queue_node() so that @q is sufficiently initialized for throtl_get_tg(). This simplifies root blkg handling noticeably for cfq and will allow further modularization of blkcg API. -v2: Vivek pointed out that using cfq_get_cfqg() won't work if CONFIG_CFQ_GROUP_IOSCHED is disabled. Fix it by factoring out initialization of base part of cfqg into cfq_init_cfqg_base() and alloc/init/free explicitly if !CONFIG_CFQ_GROUP_IOSCHED. Signed-off-by: Tejun Heo Cc: Vivek Goyal --- block/blk-core.c | 6 +- block/blk-throttle.c | 18 ++++---- block/cfq-iosched.c | 105 +++++++++++++++++++++++++------------------------- 3 files changed, 65 insertions(+), 64 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index c6c61c0..1b73d06 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -538,9 +538,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) if (err) goto fail_id; - if (blk_throtl_init(q)) - goto fail_id; - setup_timer(&q->backing_dev_info.laptop_mode_wb_timer, laptop_mode_timer_fn, (unsigned long) q); setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q); @@ -562,6 +559,9 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) */ q->queue_lock = &q->__queue_lock; + if (blk_throtl_init(q)) + goto fail_id; + return q; fail_id: diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 6613de7..aeeb798 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1252,7 +1252,6 @@ void blk_throtl_drain(struct request_queue *q) int blk_throtl_init(struct request_queue *q) { struct throtl_data *td; - struct throtl_grp *tg; td = kzalloc_node(sizeof(*td), GFP_KERNEL, q->node); if (!td) @@ -1265,19 +1264,20 @@ int blk_throtl_init(struct request_queue *q) /* alloc and Init root group. */ td->queue = q; - tg = throtl_alloc_tg(td); - if (!tg) { - kfree(td); - return -ENOMEM; - } + rcu_read_lock(); + spin_lock_irq(q->queue_lock); - td->root_tg = tg; + td->root_tg = throtl_get_tg(td, &blkio_root_cgroup); - rcu_read_lock(); - throtl_init_add_tg_lists(td, tg, &blkio_root_cgroup); + spin_unlock_irq(q->queue_lock); rcu_read_unlock(); + if (!td->root_tg) { + kfree(td); + return -ENOMEM; + } + /* Attach throtl data to request queue */ q->td = td; return 0; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 8d5f371..6aeb409 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -229,7 +229,7 @@ struct cfq_data { struct request_queue *queue; /* Root service tree for cfq_groups */ struct cfq_rb_root grp_service_tree; - struct cfq_group root_group; + struct cfq_group *root_group; /* * The priority currently being served @@ -1012,6 +1012,25 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, cfq_blkiocg_set_start_empty_time(&cfqg->blkg); } +/** + * cfq_init_cfqg_base - initialize base part of a cfq_group + * @cfqg: cfq_group to initialize + * + * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED + * is enabled or not. + */ +static void cfq_init_cfqg_base(struct cfq_group *cfqg) +{ + struct cfq_rb_root *st; + int i, j; + + for_each_cfqg_st(cfqg, i, j, st) + *st = CFQ_RB_ROOT; + RB_CLEAR_NODE(&cfqg->rb_node); + + cfqg->ttime.last_end_request = jiffies; +} + #ifdef CONFIG_CFQ_GROUP_IOSCHED static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) { @@ -1063,19 +1082,14 @@ static void cfq_init_add_cfqg_lists(struct cfq_data *cfqd, */ static struct cfq_group * cfq_alloc_cfqg(struct cfq_data *cfqd) { - struct cfq_group *cfqg = NULL; - int i, j, ret; - struct cfq_rb_root *st; + struct cfq_group *cfqg; + int ret; cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node); if (!cfqg) return NULL; - for_each_cfqg_st(cfqg, i, j, st) - *st = CFQ_RB_ROOT; - RB_CLEAR_NODE(&cfqg->rb_node); - - cfqg->ttime.last_end_request = jiffies; + cfq_init_cfqg_base(cfqg); /* * Take the initial reference that will be released on destroy @@ -1106,7 +1120,7 @@ cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg) * Avoid lookup in this case */ if (blkcg == &blkio_root_cgroup) - cfqg = &cfqd->root_group; + cfqg = cfqd->root_group; else cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, cfqd->queue, BLKIO_POLICY_PROP)); @@ -1166,7 +1180,7 @@ static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, } if (!cfqg) - cfqg = &cfqd->root_group; + cfqg = cfqd->root_group; cfq_init_add_cfqg_lists(cfqd, cfqg, blkcg); return cfqg; @@ -1182,7 +1196,7 @@ static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { /* Currently, all async queues are mapped to root group */ if (!cfq_cfqq_sync(cfqq)) - cfqg = &cfqq->cfqd->root_group; + cfqg = cfqq->cfqd->root_group; cfqq->cfqg = cfqg; /* cfqq reference on cfqg */ @@ -1283,7 +1297,7 @@ static bool cfq_clear_queue(struct request_queue *q) static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg) { - return &cfqd->root_group; + return cfqd->root_group; } static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) @@ -3677,9 +3691,8 @@ static void cfq_exit_queue(struct elevator_queue *e) if (wait) synchronize_rcu(); -#ifdef CONFIG_CFQ_GROUP_IOSCHED - /* Free up per cpu stats for root group */ - free_percpu(cfqd->root_group.blkg.stats_cpu); +#ifndef CONFIG_CFQ_GROUP_IOSCHED + kfree(cfqd->root_group); #endif kfree(cfqd); } @@ -3687,52 +3700,40 @@ static void cfq_exit_queue(struct elevator_queue *e) static int cfq_init_queue(struct request_queue *q) { struct cfq_data *cfqd; - int i, j; - struct cfq_group *cfqg; - struct cfq_rb_root *st; + int i; cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); if (!cfqd) return -ENOMEM; + cfqd->queue = q; + q->elevator->elevator_data = cfqd; + /* Init root service tree */ cfqd->grp_service_tree = CFQ_RB_ROOT; - /* Init root group */ - cfqg = &cfqd->root_group; - for_each_cfqg_st(cfqg, i, j, st) - *st = CFQ_RB_ROOT; - RB_CLEAR_NODE(&cfqg->rb_node); - - /* Give preference to root group over other groups */ - cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT; - + /* Init root group and prefer root group over other groups by default */ #ifdef CONFIG_CFQ_GROUP_IOSCHED - /* - * Set root group reference to 2. One reference will be dropped when - * all groups on cfqd->cfqg_list are being deleted during queue exit. - * Other reference will remain there as we don't want to delete this - * group as it is statically allocated and gets destroyed when - * throtl_data goes away. - */ - cfqg->ref = 2; + rcu_read_lock(); + spin_lock_irq(q->queue_lock); - if (blkio_alloc_blkg_stats(&cfqg->blkg)) { - kfree(cfqg); + cfqd->root_group = cfq_get_cfqg(cfqd, &blkio_root_cgroup); + + spin_unlock_irq(q->queue_lock); + rcu_read_unlock(); +#else + cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group), + GFP_KERNEL, cfqd->queue->node); + if (cfqd->root_group) + cfq_init_cfqg_base(cfqd->root_group); +#endif + if (!cfqd->root_group) { kfree(cfqd); return -ENOMEM; } - rcu_read_lock(); + cfqd->root_group->weight = 2*BLKIO_WEIGHT_DEFAULT; - cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, - cfqd->queue, 0); - rcu_read_unlock(); - cfqd->nr_blkcg_linked_grps++; - - /* Add group on cfqd->cfqg_list */ - hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); -#endif /* * Not strictly needed (since RB_ROOT just clears the node and we * zeroed cfqd on alloc), but better be safe in case someone decides @@ -3744,14 +3745,14 @@ static int cfq_init_queue(struct request_queue *q) /* * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. * Grab a permanent reference to it, so that the normal code flow - * will not attempt to free it. + * will not attempt to free it. oom_cfqq is linked to root_group + * but shouldn't hold a reference as it'll never be unlinked. Lose + * the reference from linking right away. */ cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); cfqd->oom_cfqq.ref++; - cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); - - cfqd->queue = q; - q->elevator->elevator_data = cfqd; + cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group); + cfq_put_cfqg(cfqd->root_group); init_timer(&cfqd->idle_slice_timer); cfqd->idle_slice_timer.function = cfq_idle_slice_timer; -- 1.7.7.3 -- 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/