Messages in this thread | | | Subject | Re: [PATCH 1/3] perf: add context field to perf_event | From | Peter Zijlstra <> | Date | Tue, 12 Jul 2011 11:18:55 +0200 |
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On Tue, 2011-07-12 at 12:16 +0300, Avi Kivity wrote: > On 07/12/2011 12:14 PM, Peter Zijlstra wrote: > > On Tue, 2011-07-12 at 12:08 +0300, Avi Kivity wrote: > > > Similar, but with stronger guarantees: when the function is called, > > > current == p, and the task was either sleeping or in userspace. > > > > If the task is sleeping, current can never be p. > > The guarantee is that the task was sleeping just before the function is > called. Of course it's woken up to run the function. > > The idea is that you run the function in a known safe point to avoid > extra synchronization. >
I'd much rather we didn't wake the task and let it sleep, that's usually a very safe place for tasks to be. All you'd need is a guarantee it won't be woken up while you're doing your thing.
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