[lkml]   [2010]   [Aug]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] mm: fix hang on anon_vma->root->lock
On 08/26/2010 02:12 AM, Hugh Dickins wrote:
> After several hours, kbuild tests hang with anon_vma_prepare() spinning on
> a newly allocated anon_vma's lock - on a box with CONFIG_TREE_PREEMPT_RCU=y
> (which makes this very much more likely, but it could happen without).
> The ever-subtle page_lock_anon_vma() now needs a further twist: since
> anon_vma_prepare() and anon_vma_fork() are liable to change the ->root
> of a reused anon_vma structure at any moment, page_lock_anon_vma()
> needs to check page_mapped() again before succeeding, otherwise
> page_unlock_anon_vma() might address a different root->lock.
> Signed-off-by: Hugh Dickins<>

Reviewed-by: Rik van Riel <>

And yes, AFAIK this code lived just in -mm up to now.

All rights reversed

 \ /
  Last update: 2010-08-26 15:35    [W:1.184 / U:0.016 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site