lkml.org 
[lkml]   [2012]   [Dec]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 7/7] mm: reduce rmap overhead for ex-KSM page copies created on swap faults
On Wed, Dec 19, 2012 at 02:01:19AM -0500, Simon Jeons wrote:
> On Mon, 2012-12-17 at 13:12 -0500, Johannes Weiner wrote:
> > When ex-KSM pages are faulted from swap cache, the fault handler is
> > not capable of re-establishing anon_vma-spanning KSM pages. In this
> > case, a copy of the page is created instead, just like during a COW
> > break.
> >
> > These freshly made copies are known to be exclusive to the faulting
> > VMA and there is no reason to go look for this page in parent and
> > sibling processes during rmap operations.
> >
> > Use page_add_new_anon_rmap() for these copies. This also puts them on
> > the proper LRU lists and marks them SwapBacked, so we can get rid of
> > doing this ad-hoc in the KSM copy code.
>
> Is it just a code cleanup instead of reduce rmap overhead?

Both.


\
 
 \ /
  Last update: 2012-12-19 19:21    [W:0.313 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site