On Tue 13-09-16 13:27:39, Sonny Rao wrote: > On Tue, Sep 13, 2016 at 12:12 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > On Mon 12-09-16 10:28:53, Sonny Rao wrote: > >> On Mon, Sep 12, 2016 at 10:15 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > >> > On Mon 12-09-16 08:31:36, Sonny Rao wrote: > > [...] > >> >> 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. > > Yes your description of what we want is pretty good. Having a > reasonable lower bound on the estimate is fine, though we probably > want to break out swapped out memory separately. Why would you want to separate that? > Given that smaps > doesn't provide this in a straightforward way, what do you think is > the right way to provide this information? I would be tempted to sneak it into /proc/<pid>/statm because that looks like a proper place but getting this information is not for free performance wise so I am not really sure something that relies on this file would see unexpected stalls. Maybe this could be worked around by some caching... I would suggest to check who is actually using this file (top/ps etc...) If this would be unacceptable then a new file could be considered. -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
