Re: [PACTH v1] mm, proc: Implement /proc/<pid>/totmaps
From: Sonny Rao
Date: Tue Aug 09 2016 - 14:29:04 EST
On Tue, Aug 9, 2016 at 9:58 AM, Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
>
> On Tue, Aug 09, 2016 at 12:05:43PM -0400, robert.foss@xxxxxxxxxxxxx wrote:
> > From: Sonny Rao <sonnyrao@xxxxxxxxxxxx>
> >
> > This is based on earlier work by Thiago Goncales. It implements a new
> > per process proc file which summarizes the contents of the smaps file
> > but doesn't display any addresses. It gives more detailed information
> > than statm like the PSS (proprotional set size). It differs from the
> > original implementation in that it doesn't use the full blown set of
> > seq operations, uses a different termination condition, and doesn't
> > displayed "Locked" as that was broken on the original implemenation.
> >
> > This new proc file provides information faster than parsing the potentially
> > huge smaps file.
>
> You can "parse" /proc/*/pagemap . RSS, swap are there.
/proc/*pagemap is generally restricted and I don't believe it would
quickly give PSS.
>
> So which ones do you really need?
PSS and Swap are the most important. RSS isn't precise enough because
it counts shared pages fully, and there tends to be a lot of sharing.
> Why the separate anon hugepages and anon regular pages?
I'm not sure if it's necessary, but that's how it's broken out in smaps.
>
> > + seq_printf(m,
> > + "Rss: %8lu kB\n"
> > + "Pss: %8lu kB\n"
> > + "Shared_Clean: %8lu kB\n"
> > + "Shared_Dirty: %8lu kB\n"
> > + "Private_Clean: %8lu kB\n"
> > + "Private_Dirty: %8lu kB\n"
> > + "Referenced: %8lu kB\n"
> > + "Anonymous: %8lu kB\n"
> > + "AnonHugePages: %8lu kB\n"
> > + "Swap: %8lu kB\n",
> > + mss_sum->resident >> 10,
> > + (unsigned long)(mss_sum->pss >> (10 + PSS_SHIFT)),
> > + mss_sum->shared_clean >> 10,
> > + mss_sum->shared_dirty >> 10,
> > + mss_sum->private_clean >> 10,
> > + mss_sum->private_dirty >> 10,
> > + mss_sum->referenced >> 10,
> > + mss_sum->anonymous >> 10,
> > + mss_sum->anonymous_thp >> 10,
> > + mss_sum->swap >> 10);