On Wed, 26 May 2010 15:40:44 -0400 Rik van Riel <riel@xxxxxxxxxx> 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 <riel@xxxxxxxxxx> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>