• Mel Gorman's avatar
    mm: uninline page_xchg_last_nid() · 4468b8f1
    Mel Gorman authored
    Andrew Morton pointed out that page_xchg_last_nid() and
    reset_page_last_nid() were "getting nuttily large" and asked that it be
    investigated.
    
    reset_page_last_nid() is on the page free path and it would be
    unfortunate to make that path more expensive than it needs to be.  Due
    to the internal use of page_xchg_last_nid() it is already too expensive
    but fortunately, it should also be impossible for the page->flags to be
    updated in parallel when we call reset_page_last_nid().  Instead of
    unlining the function, it uses a simplier implementation that assumes no
    parallel updates and should now be sufficiently short for inlining.
    
    page_xchg_last_nid() is called in paths that are already quite expensive
    (splitting huge page, fault handling, migration) and it is reasonable to
    uninline.  There was not really a good place to place the function but
    mm/mmzone.c was the closest fit IMO.
    
    This patch saved 128 bytes of text in the vmlinux file for the kernel
    configuration I used for testing automatic NUMA balancing.
    Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    4468b8f1
mmzone.c 2.36 KB