From 001bea73e70efdf48a9e00188cf302f6b6aed2bf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Aug 2015 14:55:11 -0700 Subject: blkcg: replace blkcg_policy->pd_size with ->pd_alloc/free_fn() methods A blkg (blkcg_gq) represents the relationship between a cgroup and request_queue. Each active policy has a pd (blkg_policy_data) on each blkg. The pd's were allocated by blkcg core and each policy could request to allocate extra space at the end by setting blkcg_policy->pd_size larger than the size of pd. This is a bit unusual but was done this way mostly to simplify error handling and all the existing use cases could be handled this way; however, this is becoming too restrictive now that percpu memory can be allocated without blocking. This introduces two new mandatory blkcg_policy methods - pd_alloc_fn() and pd_free_fn() - which are used to allocate and release pd for a given policy. As pd allocation is now done from policy side, it can simply allocate a larger area which embeds pd at the beginning. This change makes ->pd_size pointless. Removed. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-throttle.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'block/blk-throttle.c') diff --git a/block/blk-throttle.c b/block/blk-throttle.c index b231935..f1dd691 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -403,6 +403,11 @@ static void throtl_service_queue_exit(struct throtl_service_queue *sq) del_timer_sync(&sq->pending_timer); } +static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node) +{ + return kzalloc_node(sizeof(struct throtl_grp), gfp, node); +} + static void throtl_pd_init(struct blkcg_gq *blkg) { struct throtl_grp *tg = blkg_to_tg(blkg); @@ -493,6 +498,11 @@ static void throtl_pd_exit(struct blkcg_gq *blkg) throtl_service_queue_exit(&tg->service_queue); } +static void throtl_pd_free(struct blkg_policy_data *pd) +{ + kfree(pd); +} + static void throtl_pd_reset_stats(struct blkcg_gq *blkg) { struct throtl_grp *tg = blkg_to_tg(blkg); @@ -1468,12 +1478,13 @@ static void throtl_shutdown_wq(struct request_queue *q) } static struct blkcg_policy blkcg_policy_throtl = { - .pd_size = sizeof(struct throtl_grp), .cftypes = throtl_files, + .pd_alloc_fn = throtl_pd_alloc, .pd_init_fn = throtl_pd_init, .pd_online_fn = throtl_pd_online, .pd_exit_fn = throtl_pd_exit, + .pd_free_fn = throtl_pd_free, .pd_reset_stats_fn = throtl_pd_reset_stats, }; -- cgit v1.1