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| author | Tejun Heo <tj@kernel.org> | 2012-03-08 10:54:00 -0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2012-03-20 12:45:37 +0100 |
| commit | edf1b879e308d37b5b7c414476ab39f79650a253 (patch) | |
| tree | fec2895e806eb357ba9e9ed960f8c247042d5383 /block/blk-cgroup.h | |
| parent | c4c76a05382c7d05e0b911daa58a827399e9ba1a (diff) | |
| download | lwn-edf1b879e308d37b5b7c414476ab39f79650a253.tar.gz lwn-edf1b879e308d37b5b7c414476ab39f79650a253.zip | |
blkcg: remove blkio_group->stats_lock
With recent plug merge updates, all non-percpu stat updates happen
under queue_lock making stats_lock unnecessary to synchronize stat
updates. The only synchronization necessary is stat reading, which
can be done using u64_stats_sync instead.
This patch removes blkio_group->stats_lock and adds
blkio_group_stats->syncp for reader synchronization.
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/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 8bdcf504f94b..9df5ab04b6d6 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -119,6 +119,7 @@ struct blkio_cgroup { }; struct blkio_group_stats { + struct u64_stats_sync syncp; /* total disk time and nr sectors dispatched by this group */ uint64_t time; uint64_t stat_arr[BLKIO_STAT_ARR_NR][BLKIO_STAT_TOTAL]; @@ -200,8 +201,6 @@ struct blkio_group { /* reference count */ int refcnt; - /* Need to serialize the stats in the case of reset/update */ - spinlock_t stats_lock; struct blkg_policy_data *pd[BLKIO_NR_POLICIES]; /* List of blkg waiting for per cpu stats memory to be allocated */ |