Messages in this thread | | | Date | Wed, 15 Apr 2015 18:55:41 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH V2 1/6] perf,core: allow invalid context events to be part of sw/hw groups |
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On Wed, Apr 15, 2015 at 06:21:11PM +0200, Andi Kleen wrote: > On Wed, Apr 15, 2015 at 06:15:28PM +0200, Peter Zijlstra wrote: > > On Wed, Apr 15, 2015 at 03:56:11AM -0400, Kan Liang wrote: > > > From: Kan Liang <kan.liang@intel.com> > > > > > > The pmu marked as perf_invalid_context don't have any state to switch on > > > context switch. Everything is global. So it is OK to be part of sw/hw > > > groups. > > > In sched_out/sched_in, del/add must be called, so the > > > perf_invalid_context event can be disabled/enabled accordingly during > > > context switch. The event count only be read when the event is already > > > sched_in. > > > > > > However group read doesn't work with mix events. > > > > > > For example, > > > perf record -e '{cycles,uncore_imc_0/cas_count_read/}:S' -a sleep 1 > > > It always gets EINVAL. > > > > > > This patch set intends to fix this issue. > > > perf record -e '{cycles,uncore_imc_0/cas_count_read/}:S' -a sleep 1 > > > [ perf record: Woken up 1 times to write data ] > > > [ perf record: Captured and wrote 0.202 MB perf.data (12 samples) ] > > > > > > This patch special case invalid context events and allow them to be part > > > of sw/hw groups. > > > > I don't get it. What, Why? > > Without the patch you can't mix uncore and cpu core events in the same > group. > > Collecting uncore in PMIs is useful, for example to get memory > bandwidth over time.
Well, start with a coherent changelog, why do you still think those are optional?
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