Evicting Anonymous pages.

Mulyadi Santosa mulyadi.santosa at gmail.com
Tue Sep 27 14:12:10 EDT 2011

Hi :)

On Wed, Sep 28, 2011 at 00:14, Prateek Sharma <prateek3.14 at gmail.com> wrote:
> Hello everyone,
>  I am trying to understand the kernel page frame reclaiming
> mechanism, but one thing's bothering me:
> How does the kernel 'know' which anonymous pages to evict? In the LRU
> scheme,  'referenced/used' information for each page is required
> (AFAIK). But anonymous pages can be used by user processes 'at any
> time' without the kernel knowing about it.

Same question hog my mind too so far :)

The only satisfying self answer I could deduce is:
kernel can't track every access to pages when you do it like e.g mov
%ax,8(%esp). What kernel could track is when you access data via
wrappers. I forgot which ones, but remember some of them are updating
those "referenced" etc flags. Perhaps something like get_pages or


Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com

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