Messages in this thread | | | From | Matt Fleming <> | Subject | Re: [PATCH 2/3] perf: Remove dead code in buildin-record.c | Date | Sun, 18 Jul 2010 21:06:11 +0100 |
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On Sat, 26 Jun 2010 16:14:46 +0100, Matt Fleming <matt@console-pimps.org> wrote: > On Fri, 25 Jun 2010 16:48:05 +0200, Peter Zijlstra <peterz@infradead.org> wrote: > > > > Ah, yes, it would be nice for SH (which doesn't have a PMI) to couple a > > software timer with their hardware counter to get samples. > > > > Never got around to actually implementing that though, maybe Paul has a > > minion interested in making that work? > > I'll take a look at it.
How does the 'group_fd' parameter relate to the lack of PMI? Is the idea to have one hrtimer that, when it fires, we sample all the counters? So the first counter to be created is the group leader, which starts the hrtimer, and all other counters are linked to this one? I had a go at using a hrtimer per counter (minus any weighting of samples) and it worked OK and seemed sensible given that we may want to sample counters at different frequencies.
Is this what you had in mind with the 'group_fd' paramter, Peter? That there'd be only one hrtimer?
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