Re: [PATCH v5 0/3] mm, proc: Implement /proc/<pid>/totmaps

On Mon 12-09-16 10:28:53, Sonny Rao wrote:

On Mon, Sep 12, 2016 at 10:15 AM, Michal Hocko [off-list ref] wrote:

quoted

On Mon 12-09-16 08:31:36, Sonny Rao wrote:

[...]

quoted

quoted

but how about the other fields like Swap, Private_Dirty and
Private_Shared?

Private_Shared can be pretty confusing as well without the whole context
as well see my other emails in the original thread (just to remind
shmem/tmpfs makes all this really confusing).

But this is exactly the issue -- RSS is can be just as confusing if
you don't know something about the application.

I agree that rss can be confusing but we will not make the situation any
better if we add yet another confusing metric.

I think the issue is
how common that situation is, and you seem to believe that it's so
uncommon that it's actually better to keep the information more
difficult to get for those of us who know something about our systems.

That's fine, I guess we just have to disagree here, thanks for look at this.

I think you should just step back and think more about what exactly
you expect from the counter(s). I believe what you want is an
estimate of a freeable memory when the particular process dies or is
killed. That would mean resident single mapped private anonymous memory
+ unlinked single mapped shareable mappings + single mapped swapped out
memory. Maybe I've missed something but it should be something along
those lines. Definitely something that the current smaps infrastructure
doesn't give you, though.
-- 
Michal Hocko
SUSE Labs