lkml.org 
[lkml]   [2010]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [RFC][PATCH 07/22] sched: SCHED_DEADLINE push and pull logic
    From
    Date
    On Fri, 2010-11-12 at 17:17 +0100, Peter Zijlstra wrote:
    > On Fri, 2010-10-29 at 08:32 +0200, Raistlin wrote:
    > > Add dynamic migrations to SCHED_DEADLINE, so that tasks can
    > > be moved among CPUs when necessary. It is also possible to bind a
    > > task to a (set of) CPU(s), thus restricting its capability of
    > > migrating, or forbidding migrations at all.
    > >
    > > The very same approach used in sched_rt is utilised:
    > > - -deadline tasks are kept into CPU-specific runqueues,
    > > - -deadline tasks are migrated among runqueues to achieve the
    > > following:
    > > * on an M-CPU system the M earliest deadline ready tasks
    > > are always running;
    > > * affinity/cpusets settings of all the -deadline tasks is
    > > always respected.
    >
    > I haven't fully digested the patch, I keep getting side-tracked and its
    > a large patch..
    >
    Yeah, I know, take your time. :-)

    > however, I thought we would only allow 2 affinities,
    > strict per-cpu and full root-domain?
    >
    Yes, we do! Writing a better changelog for this already noted for next
    version.

    > Keep 2 per-cpu utilization counts, a hard-rt and a soft-rt, and ensure
    > the sum stays <= 1. Use the hard-rt one for the planned SF_HARD_RT flag,
    > use the soft-rt one for !SF_HARD_RT with nr_cpus_allowed == 1, and use
    > \Sum (1-h-s) over the root domain for nr_cpus_allowed != 1.
    >
    As agreed during LPC, that's exactly what I'll do. Let's hope to don't
    screw up while trying to do the math! :-P

    Thanks,
    Dario
    --
    <<This happens because I choose it to happen!>> (Raistlin Majere)
    ----------------------------------------------------------------------
    Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy)

    http://blog.linux.it/raistlin / raistlin@ekiga.net /
    dario.faggioli@jabber.org
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2010-11-12 22:13    [W:0.021 / U:0.924 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site