Messages in this thread | | | Date | Tue, 11 Feb 2014 17:48:05 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH 4/7] perf: be less pessimistic when scheduling events |
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On Mon, Feb 10, 2014 at 05:58:54PM +0000, Peter Zijlstra wrote: > On Mon, Feb 10, 2014 at 05:44:21PM +0000, Mark Rutland wrote: > > This patch makes ctx_flexible_sched_in attempt to schedule every group > > in the flexible_groups list even when earlier groups failed to schedule, > > enabling more groups to be scheduled simultaneously. > > Since you're basically free to create as many events as you want, you can > (as an unprivilidged user) make the context switch to and from your task > arbitrarily expensive.
Not that it makes the approach any better, but surely this is already the case for software events? I can create as many as I want, and they'll always try to schedule.
I'll take a look into other ways to stop disparate PMUs' events from adversely affecting each other. I guess it might not be possible to solve the general problem without allowing said expensive context switch.
Thanks, Mark.
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