lkml.org 
[lkml]   [2018]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 4/4] sched/numa: Do not move imbalanced load purely on the basis of an idle CPU
    * Mel Gorman <mgorman@techsingularity.net> [2018-09-10 10:41:47]:

    > On Fri, Sep 07, 2018 at 01:37:39PM +0100, Mel Gorman wrote:
    > > > Srikar's patch here:
    > > >
    > > > http://lkml.kernel.org/r/1533276841-16341-4-git-send-email-srikar@linux.vnet.ibm.com
    > > >
    > > > Also frobs this condition, but in a less radical way. Does that yield
    > > > similar results?
    > >
    > > I can check. I do wonder of course if the less radical approach just means
    > > that automatic NUMA balancing and the load balancer simply disagree about
    > > placement at a different time. It'll take a few days to have an answer as
    > > the battery of workloads to check this take ages.
    > >
    >
    > Tests completed over the weekend and I've found that the performance of
    > both patches are very similar for two machines (both 2 socket) running a
    > variety of workloads. Hence, I'm not worried about which patch gets picked
    > up. However, I would prefer my own on the grounds that the additional
    > complexity does not appear to get us anything. Of course, that changes if
    > Srikar's tests on his larger ppc64 machines show the more complex approach
    > is justified.
    >

    Running SPECJbb2005. Higher bops are better.

    Kernel A = 4.18+ 13 sched patches part of v4.19-rc1.
    Kernel B = Kernel A + 6 patches (http://lore.kernel.org/lkml/1533276841-16341-1-git-send-email-srikar@linux.vnet.ibm.com)
    Kernel C = Kernel B - (Avoid task migration for small numa improvement) i.e
    http://lore.kernel.org/lkml/1533276841-16341-4-git-send-email-srikar@linux.vnet.ibm.com
    + 2 patches from Mel
    (Do not move imbalanced load purely)
    http://lore.kernel.org/lkml/20180907101139.20760-5-mgorman@techsingularity.net
    (Stop comparing tasks for NUMA placement)
    http://lore.kernel.org/lkml/20180907101139.20760-4-mgorman@techsingularity.net

    To me, Kernel B which is the 13 patches accepted in v4.19-rc1 + 6 patches
    posted for review seem to be giving better performance.

    The numbers are compared to previous kernel i.e
    for Kernel A, v4.18 is prev
    for kernel B, Kernel A is prev
    for Kernel C, B is prev

    2 node x86 Haswell

    v4.18 or 94710cac0ef4
    JVMS Prev Current %Change
    4 203769
    1 316734

    Kernel A
    JVMS Prev Current %Change
    4 203769 209790 2.95482
    1 316734 312377 -1.3756

    Kernel B
    JVMS Prev Current %Change
    4 209790 202059 -3.68511
    1 312377 326987 4.67704

    Kernel C
    JVMS Prev Current %Change
    4 202059 200681 -0.681979
    1 326987 316715 -3.14141

    ================================================


    4 Node / 2 Socket PowerNV / Power 8

    v4.18 or 94710cac0ef4
    JVMS Prev Current %Change
    8 88411.9
    1 222075

    Kernel A
    JVMS Prev Current %Change
    8 88411.9 88733.5 0.363752
    1 222075 214607 -3.36283

    Kernel B
    JVMS Prev Current %Change
    8 88733.5 89952 1.37321
    1 214607 217226 1.22037

    Kernel C
    JVMS Prev Current %Change
    8 89952 89912.9 -0.0434676
    1 217226 219281 0.946019


    ================================================


    2 Node / 2 Socket Power 9 / PowerNV

    v4.18 or 94710cac0ef4
    JVMS Prev Current %Change
    4 195989
    1 202854

    Kernel A
    JVMS Prev Current %Change
    4 195989 193108 -1.46998
    1 202854 204042 0.585643

    Kernel B
    JVMS Prev Current %Change
    4 193108 196422 1.71614
    1 204042 211219 3.51741

    Kernel C
    JVMS Prev Current %Change
    4 196422 195052 -0.697478
    1 211219 207854 -1.59313


    ================================================

    4 Node / 4 Socket Power 7 PhyP LPAR.

    v4.18 or 94710cac0ef4
    JVMS Prev Current %Change
    8 52826.9
    1 103103

    Kernel A
    JVMS Prev Current %Change
    8 52826.9 59504.4 12.6403
    1 103103 102542 -0.544116

    Kernel B
    JVMS Prev Current %Change
    8 59504.4 61674.8 3.64746
    1 102542 108211 5.52847

    Kernel C
    JVMS Prev Current %Change
    8 61674.8 57946.5 -6.04509
    1 108211 104533 -3.39892

    \
     
     \ /
      Last update: 2018-09-12 08:55    [W:4.152 / U:0.204 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site