Re: [PATCH 1/2] perf: Add munmap callback

From: Stephane Eranian
Date: Wed Oct 24 2018 - 20:44:23 EST


On Wed, Oct 24, 2018 at 5:34 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Wed, Oct 24, 2018 at 05:25:59PM -0700, Stephane Eranian wrote:
> > On Wed, Oct 24, 2018 at 5:23 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> > > That is actually a different problem. And you're right, we never did fix
> > > that.
> > >
> > it is a different problem but the solution is the same: PERF_RECORD_UNMAP!
>
> But he's not actually doing PERF_RECORD_UNMAP, nor is his perf_munmap()
> hook sufficient to actually generate those.
>
You're right. But I saw that and thought, this is going in the right
direction: tracking munmap.
I agree with you that we should use this opportunity to track unmap
for his purpose but also
the issue I raised, which needs a new record type based on the new unmap hook.

> Now I agree that if he's going to do an munmap hook, he should do it
> 'right' and at the very least allow for PERF_RECORD_UNMAP to be done,
> but ideally simply pick up and finish that patch we had back then.
Agreed.