• Johannes Weiner's avatar
    mm: fix GFP_THISNODE callers and clarify · e97ca8e5
    Johannes Weiner authored
    GFP_THISNODE is for callers that implement their own clever fallback to
    remote nodes.  It restricts the allocation to the specified node and
    does not invoke reclaim, assuming that the caller will take care of it
    when the fallback fails, e.g.  through a subsequent allocation request
    without GFP_THISNODE set.
    
    However, many current GFP_THISNODE users only want the node exclusive
    aspect of the flag, without actually implementing their own fallback or
    triggering reclaim if necessary.  This results in things like page
    migration failing prematurely even when there is easily reclaimable
    memory available, unless kswapd happens to be running already or a
    concurrent allocation attempt triggers the necessary reclaim.
    
    Convert all callsites that don't implement their own fallback strategy
    to __GFP_THISNODE.  This restricts the allocation a single node too, but
    at the same time allows the allocator to enter the slowpath, wake
    kswapd, and invoke direct reclaim if necessary, to make the allocation
    happen when memory is full.
    Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
    Acked-by: default avatarRik van Riel <riel@redhat.com>
    Cc: Jan Stancek <jstancek@redhat.com>
    Cc: Mel Gorman <mgorman@suse.de>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    e97ca8e5
uncached.c 7.51 KB