Messages in this thread |  | | | Date | Mon, 18 Jan 2010 17:18:38 +0100 | | From | Frederic Weisbecker <> | | Subject | Re: [PATCH] perf_events: improve x86 event scheduling (v5) |
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On Mon, Jan 18, 2010 at 03:56:41PM +0100, Peter Zijlstra wrote: > On Mon, 2010-01-18 at 15:45 +0100, Frederic Weisbecker wrote: > > > > > > That requires to know in advance if we have hardware pmu > > > > in the list though (can be a flag in the group). > > > > > > Good point, but your proposed hw_check_constraint() call needs to know > > > the exact same. > > > > > > True. Whatever model we use anyway, both implement the same idea. > > Hmm, we seem to already have that problem (which would indicate another > bug in the hw-breakpoint stuff), how do you deal with > hw_perf_{enable,disable}() for the breakpoints?
We don't have ordering constraints for breakpoints, only constraints on the number of available registers.
So we check the constraints when a breakpoint registers. The enable/disable then (is supposed to) always succeed on breakpoint pmu, except for flexible breakpoints that can make it or not, but no need to overwrite group scheduling for that.
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