Re: [PATCH -mm v9 0/8] idle memory tracking

Michel Lespinasse
2015-07-29T15:34:52Z

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On Wed, Jul 29, 2015 at 8:31 AM, Vladimir Davydov <vdavydov@parallels.com>
wrote:

> On Wed, Jul 29, 2015 at 08:08:22AM -0700, Michel Lespinasse wrote:
> > On Wed, Jul 29, 2015 at 7:45 AM, Vladimir Davydov <
> vdavydov@parallels.com>
> > wrote:
> > > Page table scan approach has the inherent problem - it ignores unmapped
> > > page cache. If a workload does a lot of read/write or map-access-unmap
> > > operations, we won't be able to even roughly estimate its wss.
> >
> > You can catch that in mark_page_accessed on those paths, though.
>
> Actually, the problem here is how to find an unmapped page cache page
> *to mark it idle*, not to mark it accessed.
>

Ah, yes.

When I tried that I was still scanning memory by address at the end just to
compute such totals - but I did not have to do rmap at that point anymore.

It did look incredibly lame, though.

--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.

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