[lkml]   [2010]   [May]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 4/5] always lock the root (oldest) anon_vma
On Wed, 26 May 2010 15:40:44 -0400
Rik van Riel <> wrote:

> Subject: always lock the root (oldest) anon_vma
> Always (and only) lock the root (oldest) anon_vma whenever we do something in an
> anon_vma. The recently introduced anon_vma scalability is due to the rmap code
> scanning only the VMAs that need to be scanned. Many common operations still
> took the anon_vma lock on the root anon_vma, so always taking that lock is not
> expected to introduce any scalability issues.
> However, always taking the same lock does mean we only need to take one lock,
> which means rmap_walk on pages from any anon_vma in the vma is excluded from
> occurring during an munmap, expand_stack or other operation that needs to
> exclude rmap_walk and similar functions.
> Also add the proper locking to vma_adjust.
> Signed-off-by: Rik van Riel <>

Reviewed-by: KAMEZAWA Hiroyuki <>

 \ /
  Last update: 2010-05-27 03:05    [W:0.080 / U:82.480 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site