Re: [PATCH 4/5] perf arm-spe: Implement find_snapshot callback

Leo Yan
2021-10-06T09:51:34Z

On Wed, Oct 06, 2021 at 10:35:20AM +0100, German Gomez wrote:

[...]

> > So simply say, I think the head pointer monotonically increasing is
> > the right thing to do in Arm SPE driver.
>
> I will talk to James about how we can proceed on this.

Thanks!

> >> (note that the patch will skip the wrap-around detection if this is the
> >> case,
> >> in order to handle both cases in the userspace perf tool).
> > Almost agree, I read multiple times but have no idea what's the
> > "both cases" in the last sentence.
>
> Apologies for the later part was not clear. What I meant to say was that
> in the original patch for cs-etm, it seemed to handle both cases where
> AUX head might be monotonically and non-monotonically increasing, so we
> applied the same for the Arm SPE patch.

No worries, thanks for explanation.

Leo