Re: [PATCH V3 01/13] perf/core, x86: Add PERF_SAMPLE_DATA_PAGE_SIZE

[Will Deacon]

On Thu, Jan 31, 2019 at 01:37:25PM +0100, Peter Zijlstra wrote:
> On Wed, Jan 30, 2019 at 06:23:42AM -0800, kan.liang@xxxxxxxxxxxxxxx wrote:
> > +enum perf_page_size {
> > +	PERF_PAGE_SIZE_NONE,
> > +	PERF_PAGE_SIZE_4K,
> > +	PERF_PAGE_SIZE_8K,
> > +	PERF_PAGE_SIZE_16K,
> > +	PERF_PAGE_SIZE_64K,
> > +	PERF_PAGE_SIZE_2M,
> > +	PERF_PAGE_SIZE_1G,
> > +	PERF_PAGE_SIZE_512G,
> > +};
> 
> Since you have a u64 to store this in, WTH do you use this limited enum?
> Are you very sure this covers all the possible page sizes for all
> architectures?

FWIW, this covers the basic page sizes on arm64, but it doesn't cover all of
the hugepage sizes.

Will