Messages in this thread |  | | | Subject | Re: [RFC][PATCH 5/5] perfcounter: Add support for kernel hardware breakpoints | | From | Peter Zijlstra <> | | Date | Tue, 28 Jul 2009 09:26:40 +0200 |
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On Tue, 2009-07-28 at 02:18 +0200, Frederic Weisbecker wrote: > > I still don't understand why it is needed to reserve breakpoints for > a group of monitored tasks. Once they have registered their breakpoints, > the number of necessary hardware registers for these will be available > every time the task is scheduled.
Its possible to create >4 breakpoint counters. We time-share them.
The only constraint we have is that those within a group should be on the 'PMU' at the same time.
If you have no groups, a single available breakpoint slot should suffice for any configuration (although more is better), but if you get groups you have to guarantee your created group can run.
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