Re: [RFC][PATCH] perf: Rewrite core context handling

From: Peter Zijlstra
Date: Fri Oct 12 2018 - 07:54:44 EST


On Fri, Oct 12, 2018 at 10:04:36AM +0300, Alexey Budankov wrote:
> On 11.10.2018 12:29, Peter Zijlstra wrote:
> > On Thu, Oct 11, 2018 at 07:50:23AM +0000, Song Liu wrote:
> >> Or step back a little... I see two big changes:
> >>
> >> 1. struct perf_ctx_context is now per cpu (instead of per pmu per cpu);
> >> 2. one perf_event_ctxp per task_struct (instead of 2).
> >
> > Correct, we reduce to 1 cpu context and 1 task context at all times.
> > This in fact simplifies quite a bit of things.
>
> And what is currently missing is
> some markup of the per cpu event list into per pmu sublists and
> capability to rotate or not rotate the sublists independently,
> right?

Yes, that is what the new perf_event_pmu_context is. That tracks the per
pmu sublist state.