• Mel Gorman's avatar
    mm: use two zonelist that are filtered by GFP mask · 54a6eb5c
    Mel Gorman authored
    
    
    Currently a node has two sets of zonelists, one for each zone type in the
    system and a second set for GFP_THISNODE allocations.  Based on the zones
    allowed by a gfp mask, one of these zonelists is selected.  All of these
    zonelists consume memory and occupy cache lines.
    
    This patch replaces the multiple zonelists per-node with two zonelists.  The
    first contains all populated zones in the system, ordered by distance, for
    fallback allocations when the target/preferred node has no free pages.  The
    second contains all populated zones in the node suitable for GFP_THISNODE
    allocations.
    
    An iterator macro is introduced called for_each_zone_zonelist() that interates
    through each zone allowed by the GFP flags in the selected zonelist.
    Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
    Acked-by: default avatarChristoph Lameter <clameter@sgi.com>
    Signed-off-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
    Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
    Cc: Mel Gorman <mel@csn.ul.ie>
    Cc: Christoph Lameter <clameter@sgi.com>
    Cc: Hugh Dickins <hugh@veritas.com>
    Cc: Nick Piggin <nickpiggin@yahoo.com.au>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    54a6eb5c