lkml.org 
[lkml]   [2007]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 5/6] sched: SCHED_FIFO/SCHED_RR watchdog timer
    On Wed, Oct 31, 2007 at 11:03:28PM +0100, Peter Zijlstra wrote:
    >
    > On Wed, 2007-10-31 at 22:49 +0100, Andi Kleen wrote:
    > > Peter Zijlstra <a.p.zijlstra@chello.nl> writes:
    > >
    > > > Introduce a new rlimit that allows the user to set a runtime timeout
    > > > on real-time tasks. Once this limit is exceeded the task will receive
    > > > SIGXCPU.
    > >
    > > Nice idea.
    > >
    > > It would be even nicer if you could allow a couple of them. Partition
    > > the RT priorities into a few classes and have an own limit for each them.
    > >
    > > A small number of classes (3-4) would be probably enough and not bloat
    > > the rlimits too much.
    > >
    > > I'm thinking of the case where you have different kinds of real
    > > time processes. Like your mp3 player which you want to be slightly
    > > real time, but with a low SIGXCPU limit.
    > >
    > > And then something else real time which is more important and
    > > you would set a higher limit. etc.
    >
    > But its an rlimit, it can be set per process. Not sure what multiple

    That's impractical -- you would need to patch the process or call
    it from a special program, which is not nice.

    rlimits are useful to set a limit during log in. For that the
    children can be all kinds of different processes and possibly use
    different settings.

    > classes per process would gain us, let alone how that process has to
    > figure out which class to use.

    You set the classes once per rlimit (e.g. in a pam module)
    Then the processes set different scheduling priorities by themselves
    (standard programs do that). Then that priority would map to a different
    class.

    -Andi

    -
    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: 2007-11-03 19:19    [W:0.022 / U:29.564 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site