aboutsummaryrefslogtreecommitdiffstats
path: root/block
diff options
context:
space:
mode:
authorTejun Heo <tj@kernel.org>2012-03-19 15:10:56 -0700
committerJens Axboe <axboe@kernel.dk>2012-03-20 12:47:47 +0100
commit9a9e8a26da4c2c5ddc60999bdea957935fb22b6b (patch)
tree5a42ef29c2c34174390e4ccf9a2924c0ade6f340 /block
parentblkcg: remove blkio_group->stats_lock (diff)
downloadlinux-dev-9a9e8a26da4c2c5ddc60999bdea957935fb22b6b.tar.xz
linux-dev-9a9e8a26da4c2c5ddc60999bdea957935fb22b6b.zip
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 <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-cgroup.c3
-rw-r--r--block/blk-cgroup.h3
2 files changed, 6 insertions, 0 deletions
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 <linux/slab.h>
#include <linux/genhd.h>
#include <linux/delay.h>
+#include <linux/atomic.h>
#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 {