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>
This commit is contained in:
Tejun Heo 2012-03-19 15:10:56 -07:00 committed by Jens Axboe
parent edf1b879e3
commit 9a9e8a26da
2 changed files with 6 additions and 0 deletions

View File

@ -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);

View File

@ -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 {