Re: [PATCH -mm] Shared Page accounting for memory cgroup (v2)

From: Balbir Singh
Date: Tue Jan 05 2010 - 22:08:05 EST


* KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2010-01-06 09:07:08]:

> On Wed, 6 Jan 2010 00:22:26 +0530
> Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx> wrote:
>
> > Hi, All,
> >
> > No major changes from v1, except for the use of get_mm_rss().
> > Kamezawa-San felt that this can be done in user space and I responded
> > to him with my concerns of doing it in user space. The thread
> > can be found at http://thread.gmane.org/gmane.linux.kernel.mm/42367.
> >
> > If there are no major objections, can I ask for a merge into -mm.
> > Andrew, the patches are against mmotm 10 December 2009, if there
> > are some merge conflicts, please let me know, I can rebase after
> > you release the next mmotm.
> >
>
> The problem is that this isn't "shared" uasge but "considered to be shared"
> usage. Okay ?
>

Could you give me your definition of "shared". From the mem cgroup
perspective, total_rss (which is accumulated) subtracted from the
count of pages in the LRU which are RSS and FILE_MAPPED is shared, no?
I understand that some of the pages that might be shared, show up
in our LRU and accounting. These are not treated as shared by
our cgroup, but by other cgroups.

> Then I don't want to provide this misleading value as "official report" from
> the kernel. And this can be done in userland.
>

I explained some of the issues of doing this from user space, would
you be OK if I called them "non-private" pages?

--
Balbir
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