lkml.org 
[lkml]   [2010]   [Apr]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: hackbench regression due to commit 9dfc6e68bfe6e
    From
    Date
    Le jeudi 08 avril 2010 à 07:39 +0200, Eric Dumazet a écrit :
    > I suspect NUMA is completely out of order on current kernel, or my
    > Nehalem machine NUMA support is a joke
    >
    > # numactl --hardware
    > available: 2 nodes (0-1)
    > node 0 size: 3071 MB
    > node 0 free: 2637 MB
    > node 1 size: 3062 MB
    > node 1 free: 2909 MB
    >
    >
    > # cat try.sh
    > hackbench 50 process 5000
    > numactl --cpubind=0 --membind=0 hackbench 25 process 5000 >RES0 &
    > numactl --cpubind=1 --membind=1 hackbench 25 process 5000 >RES1 &
    > wait
    > echo node0 results
    > cat RES0
    > echo node1 results
    > cat RES1
    >
    > numactl --cpubind=0 --membind=1 hackbench 25 process 5000 >RES0_1 &
    > numactl --cpubind=1 --membind=0 hackbench 25 process 5000 >RES1_0 &
    > wait
    > echo node0 on mem1 results
    > cat RES0_1
    > echo node1 on mem0 results
    > cat RES1_0
    >
    > # ./try.sh
    > Running with 50*40 (== 2000) tasks.
    > Time: 16.865
    > node0 results
    > Running with 25*40 (== 1000) tasks.
    > Time: 16.767
    > node1 results
    > Running with 25*40 (== 1000) tasks.
    > Time: 16.564
    > node0 on mem1 results
    > Running with 25*40 (== 1000) tasks.
    > Time: 16.814
    > node1 on mem0 results
    > Running with 25*40 (== 1000) tasks.
    > Time: 16.896

    If run individually, the tests results are more what we would expect
    (slow), but if machine runs the two set of process concurrently, each
    group runs much faster...


    # numactl --cpubind=0 --membind=1 hackbench 25 process 5000
    Running with 25*40 (== 1000) tasks.
    Time: 21.810

    # numactl --cpubind=1 --membind=0 hackbench 25 process 5000
    Running with 25*40 (== 1000) tasks.
    Time: 20.679

    # numactl --cpubind=0 --membind=1 hackbench 25 process 5000 >RES0_1 &
    [1] 9177
    # numactl --cpubind=1 --membind=0 hackbench 25 process 5000 >RES1_0 &
    [2] 9196
    # wait
    [1]- Done numactl --cpubind=0 --membind=1 hackbench
    25 process 5000 >RES0_1
    [2]+ Done numactl --cpubind=1 --membind=0 hackbench
    25 process 5000 >RES1_0
    # echo node0 on mem1 results
    node0 on mem1 results
    # cat RES0_1
    Running with 25*40 (== 1000) tasks.
    Time: 13.818
    # echo node1 on mem0 results
    node1 on mem0 results
    # cat RES1_0
    Running with 25*40 (== 1000) tasks.
    Time: 11.633

    Oh well...


    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2010-04-08 09:03    [W:0.028 / U:0.796 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site