Messages in this thread | | | Date | Thu, 21 Jul 2011 17:37:57 +0100 | From | Will Deacon <> | Subject | Re: [PATCH 1/3] perf: add context field to perf_event |
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On Thu, Jul 21, 2011 at 04:59:00PM +0100, Avi Kivity wrote: > On 07/21/2011 06:46 PM, Will Deacon wrote: > > > > > > This is (and must be) called from a preempt disabled context, no mutexes > > > around here. > > > > Bah, yes, that is essential if you're dealing with current. Maybe use a > > spinlock instead? > > Could work. Not thrilled about adding it to the kvm hot path, but I > can't say it will make a measurable impact.
Understood, but at least it doesn't contribute to finish_task_switch. I also wouldn't expect to have multiple preempt registrations in parallel for the same task so that lock should rarely (if ever) be contended.
Will
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