• Anton Blanchard's avatar
    powerpc/numa: Enable SD_WAKE_AFFINE in node definition · a200d8e4
    Anton Blanchard authored
    When chasing a performance issue on ppc64, I noticed tasks
    communicating via a pipe would often end up on different nodes.
    
    It turns out SD_WAKE_AFFINE is not set in our node defition. Commit
    9fcd18c9 (sched: re-tune balancing) enabled SD_WAKE_AFFINE
    in the node definition for x86 and we need a similar change for
    ppc64.
    
    I used lmbench lat_ctx and perf bench pipe to verify this fix. Each
    benchmark was run 10 times and the average taken.
    
    lmbench lat_ctx:
    
    before:  66565 ops/sec
    after:  204700 ops/sec
    
    3.1x faster
    
    perf bench pipe:
    
    before: 5.6570 usecs
    after:  1.3470 usecs
    
    4.2x faster
    Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    a200d8e4
topology.h 3.5 KB