Re: [PATCH] mm: show stats for non-default hugepage sizes in /proc/meminfo

From: Roman Gushchin
Date: Tue Nov 14 2017 - 07:50:08 EST


On Mon, Nov 13, 2017 at 11:25:21AM -0800, Mike Kravetz wrote:
> On 11/13/2017 11:10 AM, Johannes Weiner wrote:
> > On Mon, Nov 13, 2017 at 06:45:01PM +0000, Roman Gushchin wrote:
> >> Or, at least, some total counter, e.g. how much memory is consumed
> >> by hugetlb pages?
> >
> > I'm not a big fan of the verbose breakdown for every huge page size.
> > As others have pointed out such detail exists elswhere.
> >
> > But I do think we should have a summary counter for memory consumed by
> > hugetlb that lets you know how much is missing from MemTotal. This can
> > be large parts of overall memory, and right now /proc/meminfo will
> > give the impression we are leaking those pages.
> >
> > Maybe a simple summary counter for everything set aside by the hugetlb
> > subsystem - default and non-default page sizes, whether they're used
> > or only reserved etc.?
> >
> > Hugetlb 12345 kB
>
> I would prefer this approach. The 'trick' is coming up with a name or
> description that is not confusing. Unfortunately, we have to leave the
> existing entries. So, this new entry will be greater than or equal to
> HugePages_Total. :( I guess Hugetlb is as good of a name as any?

Yes, I like this approach too, and Hugetlb (in kB) sounds reasonable.
I'll post a new patch soon.