commit edf1b879e308d37b5b7c414476ab39f79650a253
author Tejun Heo <tj@kernel.org> Thu Mar 08 10:54:00 2012 -0800
committer Jens Axboe <axboe@kernel.dk> Tue Mar 20 12:45:37 2012 +0100
tree fec2895e806eb357ba9e9ed960f8c247042d5383
parent c4c76a05382c7d05e0b911daa58a827399e9ba1a

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>