Messages in this thread | | | Date | Thu, 2 Feb 2012 12:36:09 -0800 | From | Tejun Heo <> | Subject | Re: [PATCHSET] blkcg: unify blkgs for different policies |
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Hello,
On Thu, Feb 02, 2012 at 02:29:58PM -0500, Vivek Goyal wrote: > On Wed, Feb 01, 2012 at 01:19:05PM -0800, Tejun Heo wrote: > > [..] > > > > * use unified stats updated under queue lock and drop percpu stats > > which should fix locking / context bug across percpu allocation. > > Does that mean that stat updation will happen under queue lock even if > there are no throttling rules? That will introduce extra queue lock on > fast path those who have throttling compiled in but are not using (common > case for distributions).
No, I don't think extra locking would be necessary at all. We end up grabbing queue_lock anyway. It's just the matter of where to update the stats.
Thanks.
-- tejun
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