diff options
| -rw-r--r-- | block/blk-cgroup.c | 55 | ||||
| -rw-r--r-- | include/linux/blk-cgroup.h | 3 |
2 files changed, 21 insertions, 37 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index f91a4e09e0c9..9e9b0df339ee 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1047,65 +1047,52 @@ EXPORT_SYMBOL_GPL(blkio_cgrp_subsys); int blkcg_activate_policy(struct request_queue *q, const struct blkcg_policy *pol) { - LIST_HEAD(pds); + struct blkg_policy_data *pd_prealloc = NULL; struct blkcg_gq *blkg; - struct blkg_policy_data *pd, *nd; - int cnt = 0, ret; + int ret; if (blkcg_policy_enabled(q, pol)) return 0; - /* count and allocate policy_data for all existing blkgs */ blk_queue_bypass_start(q); - spin_lock_irq(q->queue_lock); - list_for_each_entry(blkg, &q->blkg_list, q_node) - cnt++; - spin_unlock_irq(q->queue_lock); - - /* allocate per-blkg policy data for all existing blkgs */ - while (cnt--) { - pd = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node); - if (!pd) { +pd_prealloc: + if (!pd_prealloc) { + pd_prealloc = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node); + if (!pd_prealloc) { ret = -ENOMEM; - goto out_free; + goto out_bypass_end; } - list_add_tail(&pd->alloc_node, &pds); } - /* - * Install the allocated pds and cpds. With @q bypassing, no new blkg - * should have been created while the queue lock was dropped. - */ spin_lock_irq(q->queue_lock); list_for_each_entry(blkg, &q->blkg_list, q_node) { - if (WARN_ON(list_empty(&pds))) { - /* umm... this shouldn't happen, just abort */ - ret = -ENOMEM; - goto out_unlock; - } - pd = list_first_entry(&pds, struct blkg_policy_data, alloc_node); - list_del_init(&pd->alloc_node); + struct blkg_policy_data *pd; - /* grab blkcg lock too while installing @pd on @blkg */ - spin_lock(&blkg->blkcg->lock); + if (blkg->pd[pol->plid]) + continue; + + pd = kzalloc_node(pol->pd_size, GFP_NOWAIT, q->node); + if (!pd) + swap(pd, pd_prealloc); + if (!pd) { + spin_unlock_irq(q->queue_lock); + goto pd_prealloc; + } blkg->pd[pol->plid] = pd; pd->blkg = blkg; pd->plid = pol->plid; pol->pd_init_fn(blkg); - - spin_unlock(&blkg->blkcg->lock); } __set_bit(pol->plid, q->blkcg_pols); ret = 0; -out_unlock: + spin_unlock_irq(q->queue_lock); -out_free: +out_bypass_end: blk_queue_bypass_end(q); - list_for_each_entry_safe(pd, nd, &pds, alloc_node) - kfree(pd); + kfree(pd_prealloc); return ret; } EXPORT_SYMBOL_GPL(blkcg_activate_policy); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 9711fc277c02..db822880242a 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -80,9 +80,6 @@ struct blkg_policy_data { /* the blkg and policy id this per-policy data belongs to */ struct blkcg_gq *blkg; int plid; - - /* used during policy activation */ - struct list_head alloc_node; }; /* |