lkml.org 
[lkml]   [2012]   [May]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC] sched: make callers check lock contention for cond_resched_lock()
    On Thu, 03 May 2012 10:35:27 +0200
    Peter Zijlstra <peterz@infradead.org> wrote:

    > On Thu, 2012-05-03 at 17:12 +0900, Takuya Yoshikawa wrote:
    > >
    > > Although we can do that using spin_is_contended() and cond_resched(),
    > > changing cond_resched_lock() to satisfy such a need is another option.
    > >
    > Yeah, not a pretty patch. Changing all cond_resched_lock() sites just to
    > change one and in such an ugly way too.
    >
    > So what's the impact of making spin_needbreak() work for !PREEMPT?

    Although the real use case is out of this RFC patch, we are now discussing
    a case in which we may hold a spin_lock for long time, ms order, depending
    on workload; and in that case, other threads -- VCPU threads -- should be
    given higher priority for that problematic lock.

    I wanted to hear whether other users also have similar needs. If so, it
    may be worth making the API a bit more generic.

    But I could not find a clean solution for that. Do you think that using
    spin_is_contended() directly is the way to go?

    Thanks,
    Takuya


    \
     
     \ /
      Last update: 2012-05-03 14:41    [W:0.024 / U:91.200 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site