From 9a9e8a26da4c2c5ddc60999bdea957935fb22b6b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 19 Mar 2012 15:10:56 -0700 Subject: [PATCH] blkcg: add blkcg->id Add 64bit unique id to blkcg. This will be used by policies which want blkcg identity test to tell whether the associated blkcg has changed. Signed-off-by: Tejun Heo Cc: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 3 +++ block/blk-cgroup.h | 3 +++ 2 files changed, 6 insertions(+) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index b15a51711bca..30e07308db24 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "blk-cgroup.h" #include "blk.h" @@ -1622,6 +1623,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) static struct cgroup_subsys_state * blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) { + static atomic64_t id_seq = ATOMIC64_INIT(0); struct blkio_cgroup *blkcg; struct cgroup *parent = cgroup->parent; @@ -1635,6 +1637,7 @@ blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) return ERR_PTR(-ENOMEM); blkcg->weight = BLKIO_WEIGHT_DEFAULT; + blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */ done: spin_lock_init(&blkcg->lock); INIT_HLIST_HEAD(&blkcg->blkg_list); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 9df5ab04b6d6..1cb8f7643258 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -116,6 +116,9 @@ struct blkio_cgroup { unsigned int weight; spinlock_t lock; struct hlist_head blkg_list; + + /* for policies to test whether associated blkcg has changed */ + uint64_t id; }; struct blkio_group_stats {