Re: [PATCH 18/30] x86, kaiser: map virtually-addressed performance monitoring buffers

[Peter Zijlstra]

On Tue, Nov 14, 2017 at 11:10:23AM -0800, Hugh Dickins wrote:
> I was about to agree, but now I'm not so sure.  I don't know much
> about these PMC things, but at a glance it looks like what is reserved
> by x86_reserve_hardware() may later be released by x86_release_hardware(),
> and then later reserved again by x86_reserve_hardware().  And although
> the static per-cpu area would be zeroed the first time, the second time
> it will contain data left over from before, so really needs the memset?

Ah, yes. It does get reused. I think its still fine, but yes lets keep
it. Better safe than sorry and its not a hot path in any case.

Thanks!