• Mel Gorman's avatar
    mm: mark the correct zone as full when scanning zonelists · 5bead2a0
    Mel Gorman authored
    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: default avatarMel 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: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    5bead2a0
mmzone.c 1.47 KB