Re: [PATCH v5 2/2] mm: hugetlb: proc: add HugetlbPages field to /proc/PID/status

Jörn Engel
2015-08-21T16:30:38Z

On Fri, Aug 21, 2015 at 08:53:21AM +0200, Michal Hocko wrote:
> On Thu 20-08-15 23:34:51, Naoya Horiguchi wrote:
> [...]
> > > Reading a single file is, of course, easier but is it really worth the
> > > additional code? I haven't really looked at the patch so I might be
> > > missing something but what would be an advantage over reading
> > > /proc/<pid>/smaps and extracting the information from there?
> >
> > My first idea was just "users should feel it useful", but permission as David
> > commented sounds a good technical reason to me.
>
> 9 files changed, 112 insertions(+), 1 deletion(-)
>
> is quite a lot especially when it touches hot paths like fork so it
> better should have a good usecase. I have already asked in the other
> email but is actually anybody requesting this? Nice to have is not
> a good justification IMO.

I need some way to judge the real rss of a process, including huge
pages. No strong opinion on implementation details, but something is
clearly needed.

If you have processes with 99% huge pages, you are currently reduced to
guesswork.

Jörn

--
Journalism is printing what someone else does not want printed;
everything else is public relations.
-- George Orwell