Re: [RFC][PATCH 5/5] perfcounter: Add support for kernel hardwarebreakpoints

[Peter Zijlstra]

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.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/