Messages in this thread | | | Date | Fri, 9 Mar 2012 12:15:23 -0500 | From | Vivek Goyal <> | Subject | Re: [PATCH 5/5] blkcg: remove blkio_group->stats_lock |
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On Thu, Mar 08, 2012 at 10:54:00AM -0800, Tejun Heo wrote: > 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. >
Good to see stat_lock going away. That lock was confusing as we were doing updates under queue_lock anyway. One less lock to think about now.
This stat code is messy though. All time related stat, maintaining flags, dividing stats between read/write, sync/async. I think we are maintaining way too much of stat. (/me wished there was a way to get rid of some of the stats and make code simpler).
Thanks Vivek
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