Re: [RFC V1 04/16] perf/events: Replace READ_ONCE() with standard pgtable accessors

Peter Zijlstra
2026-02-24T10:41:45Z

On Tue, Feb 24, 2026 at 10:08:21AM +0000, Mark Rutland wrote:
> On Tue, Feb 24, 2026 at 10:41:41AM +0530, Anshuman Khandual wrote:
> > Replace READ_ONCE() with standard page table accessors i.e pxdp_get() which
> > anyways default into READ_ONCE() in cases where platform do not override.
>
> For each of the patches where you make this sort of change, please
> explain in the commit message *why* it is necessary to do this.
>
> IIUC the entire point of this is that in subsequent patches, arm64 will
> need to use something other than READ_ONCE() for all pXX levels in order
> to support D128 translation tables.
>
> Spelling that out in the commit message makes it much easier for
> reviewers to see what's going on, and to focus any discussion/questions,
> e.g. *why* won't READ_ONCE() work?

That, and only being sent *one* patch, I have no clue what the rest of
them are doing. Didn't even get 0/n.

I hate people sending me just one patch; just send the whole series
already.