From 29b125892f3317ada86b662e0b6ebc0f79be9037 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Thu, 19 May 2011 15:38:24 -0400 Subject: [PATCH] blk-throttle: Dynamically allocate root group Currently, we allocate root throtl_grp statically. But as we will be introducing per cpu stat pointers and that will be allocated dynamically even for root group, we might as well make whole root throtl_grp allocation dynamic and treat it in same manner as other groups. Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-throttle.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index c201967b33cd..68f2ac3f3b07 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -88,7 +88,7 @@ struct throtl_data /* service tree for active throtl groups */ struct throtl_rb_root tg_service_tree; - struct throtl_grp root_tg; + struct throtl_grp *root_tg; struct request_queue *queue; /* Total Number of queued bios on READ and WRITE lists */ @@ -233,7 +233,7 @@ throtl_grp *throtl_find_tg(struct throtl_data *td, struct blkio_cgroup *blkcg) * Avoid lookup in this case */ if (blkcg == &blkio_root_cgroup) - tg = &td->root_tg; + tg = td->root_tg; else tg = tg_of_blkg(blkiocg_lookup_group(blkcg, key)); @@ -313,7 +313,7 @@ static struct throtl_grp * throtl_get_tg(struct throtl_data *td) /* Group allocation failed. Account the IO to root group */ if (!tg) { - tg = &td->root_tg; + tg = td->root_tg; return tg; } @@ -1153,18 +1153,16 @@ int blk_throtl_init(struct request_queue *q) td->limits_changed = false; INIT_DELAYED_WORK(&td->throtl_work, blk_throtl_work); - /* Init root group */ - tg = &td->root_tg; - throtl_init_group(tg); + /* alloc and Init root group. */ + td->queue = q; + tg = throtl_alloc_tg(td); - /* - * Set root group reference to 2. One reference will be dropped when - * all groups on tg_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. - */ - atomic_inc(&tg->ref); + if (!tg) { + kfree(td); + return -ENOMEM; + } + + td->root_tg = tg; rcu_read_lock(); blkiocg_add_blkio_group(&blkio_root_cgroup, &tg->blkg, (void *)td, @@ -1173,7 +1171,6 @@ int blk_throtl_init(struct request_queue *q) throtl_add_group_to_td_list(td, tg); /* Attach throtl data to request queue */ - td->queue = q; q->td = td; return 0; }