lkml.org 
[lkml]   [2021]   [Sep]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 2/2] sched/fair: Scale wakeup granularity relative to nr_running
    On Mon, Sep 27, 2021 at 04:19:00PM +0200, Vincent Guittot wrote:
    > On Mon, 27 Sept 2021 at 13:17, Mel Gorman <mgorman@techsingularity.net> wrote:
    > >
    > > On Thu, Sep 23, 2021 at 02:41:06PM +0200, Vincent Guittot wrote:
    > > > On Thu, 23 Sept 2021 at 11:22, Mike Galbraith <efault@gmx.de> wrote:
    > > > >
    > > > > On Thu, 2021-09-23 at 10:40 +0200, Vincent Guittot wrote:
    > > > > >
    > > > > > a 100us value should even be enough to fix Mel's problem without
    > > > > > impacting common wakeup preemption cases.
    > > > >
    > > > > It'd be nice if it turn out to be something that simple, but color me
    > > > > skeptical. I've tried various preemption throttling schemes, and while
    > > >
    > > > Let's see what the results will show. I tend to agree that this will
    > > > not be enough to cover all use cases and I don't see any other way to
    > > > cover all cases than getting some inputs from the threads about their
    > > > latency fairness which bring us back to some kind of latency niceness
    > > > value
    > > >
    > >
    > > Unfortunately, I didn't get a complete set of results but enough to work
    > > with. The missing tests have been requeued. The figures below are based
    > > on a single-socket Skylake machine with 8 CPUs as it had the most set of
    > > results and is the basic case.
    > >
    > > The reported kernels are
    > >
    > > vanilla: vanilla 5.15-rc1
    > > sched-scalewakegran-v2r4: My patch
    > > sched-moveforward-v1r1: Vincent's patch
    >
    > I imagine that this is the results for the 1st version which scales
    > with the number of CPUs
    >

    Yes, the v1r5 results were incomplete and had to be requeued.

    --
    Mel Gorman
    SUSE Labs

    \
     
     \ /
      Last update: 2021-09-27 17:03    [W:4.248 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site