]> err.no Git - linux-2.6/commit
mm: mark the correct zone as full when scanning zonelists
authorMel Gorman <mel@csn.ul.ie>
Sat, 13 Sep 2008 09:33:19 +0000 (02:33 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 13 Sep 2008 21:41:52 +0000 (14:41 -0700)
commit5bead2a0680687b9576d57c177988e8aa082b922
tree25d8db69bd7b353131f9a5260d024d3018eeffa0
parent7e96445533ac3f4f7964646a202ff3620602fab4
mm: mark the correct zone as full when scanning zonelists

The iterator for_each_zone_zonelist() uses a struct zoneref *z cursor when
scanning zonelists to keep track of where in the zonelist it is.  The
zoneref that is returned corresponds to the the next zone that is to be
scanned, not the current one.  It was intended to be treated as an opaque
list.

When the page allocator is scanning a zonelist, it marks elements in the
zonelist corresponding to zones that are temporarily full.  As the
zonelist is being updated, it uses the cursor here;

  if (NUMA_BUILD)
        zlc_mark_zone_full(zonelist, z);

This is intended to prevent rescanning in the near future but the zoneref
cursor does not correspond to the zone that has been found to be full.
This is an easy misunderstanding to make so this patch corrects the
problem by changing zoneref cursor to be the current zone being scanned
instead of the next one.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org> [2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/mmzone.h
mm/mmzone.c