• Mel Gorman's avatar
    mm, page_alloc: reduce branches in zone_statistics · b9f00e14
    Mel Gorman authored
    zone_statistics has more branches than it really needs to take an
    unlikely GFP flag into account.  Reduce the number and annotate the
    unlikely flag.
    
    The performance difference on a page allocator microbenchmark is;
    
                                                 4.6.0-rc2                  4.6.0-rc2
                                          nocompound-v1r10           statbranch-v1r10
      Min      alloc-odr0-1               417.00 (  0.00%)           419.00 ( -0.48%)
      Min      alloc-odr0-2               308.00 (  0.00%)           305.00 (  0.97%)
      Min      alloc-odr0-4               253.00 (  0.00%)           250.00 (  1.19%)
      Min      alloc-odr0-8               221.00 (  0.00%)           219.00 (  0.90%)
      Min      alloc-odr0-16              205.00 (  0.00%)           203.00 (  0.98%)
      Min      alloc-odr0-32              199.00 (  0.00%)           195.00 (  2.01%)
      Min      alloc-odr0-64              193.00 (  0.00%)           191.00 (  1.04%)
      Min      alloc-odr0-128             191.00 (  0.00%)           189.00 (  1.05%)
      Min      alloc-odr0-256             200.00 (  0.00%)           198.00 (  1.00%)
      Min      alloc-odr0-512             212.00 (  0.00%)           210.00 (  0.94%)
      Min      alloc-odr0-1024            219.00 (  0.00%)           216.00 (  1.37%)
      Min      alloc-odr0-2048            225.00 (  0.00%)           221.00 (  1.78%)
      Min      alloc-odr0-4096            231.00 (  0.00%)           227.00 (  1.73%)
      Min      alloc-odr0-8192            234.00 (  0.00%)           232.00 (  0.85%)
      Min      alloc-odr0-16384           234.00 (  0.00%)           232.00 (  0.85%)
    Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
    Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
    Cc: Jesper Dangaard Brouer <brouer@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    b9f00e14
vmstat.c 43.8 KB