Messages in this thread | | | Subject | Re: [BUG] 2.6.37-rc3 massive interactivity regression on ARM | From | Peter Zijlstra <> | Date | Fri, 10 Dec 2010 11:08:24 +0100 |
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On Thu, 2010-12-09 at 15:35 -0800, Venkatesh Pallipadi wrote: > > Just to make sure, update_rq_clock() always gets called on current > CPU. Right?
No, specifically not. If that were the case we wouldn't need the cross-cpu synced timestamp. Things like load-balancing and remote-wakeups need to update a remote CPUs clock.
> The pending patches I have optimizes > account_system_vtime() to use this_cpu_write and friends. Want to make > sure this change will still keep that optimization relevant.
Ah, good point, remote CPUs updating that will mess with the consistency of the per-cpu timestamps due to non atomic updates :/
Bugger.. making them atomics will make it even more expensive. /me goes ponder.
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