lkml.org 
[lkml]   [2020]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 0/2] memcg: add pagetable comsumption to memory.stat
On Mon, Nov 30, 2020 at 12:34 PM Roman Gushchin <guro@fb.com> wrote:
>
> On Wed, Nov 25, 2020 at 04:56:01PM -0800, Shakeel Butt wrote:
> > Many workloads consumes significant amount of memory in pagetables. This
> > patch series exposes the pagetable comsumption for each memory cgroup.
>
> Hi Shakeel!
>
> The code looks good to me. However I'm not sure I understand what's the
> use case for the new statistics? Can you, please, elaborate a bit more here?
>
> From a very first glance, the size of pagetables should be _roughly_ equal
> to the size_of(pte)/PAGE_SIZE*(size of a cgroup) and should not exceed 1%
> of the cgroup size. So for all but very large cgroups the value will be
> in the noise of per-cpu counters. Perhaps I'm missing some important cases?
>

I think this is in general a good metric to have but one specific
use-case we have is the user space network driver which mmaps the
memory of the applications for zero copy data transfers. This driver
can consume a large amount of memory in page tables. So, this metric
becomes really useful here.

Shakeel

\
 
 \ /
  Last update: 2020-11-30 22:06    [W:0.146 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site