lkml.org 
[lkml]   [2007]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [patch] timer/hrtimer: take per cpu locks in sane order

    * Heiko Carstens <heiko.carstens@de.ibm.com> wrote:

    > - spin_lock(&new_base->lock);
    > - spin_lock(&old_base->lock);
    > + /*
    > + * If we take a lock from a different cpu, make sure we have always
    > + * the same locking order. That is the lock that belongs to the cpu
    > + * with the lowest number is taken first.
    > + */
    > + lock1 = smp_processor_id() < cpu ? &new_base->lock : &old_base->lock;
    > + lock2 = smp_processor_id() < cpu ? &old_base->lock : &new_base->lock;
    > + spin_lock(lock1);
    > + spin_lock(lock2);

    looks good to me. Wouldnt this be cleaner via double_lock_timer() -
    similar to how double_rq_lock() works in kernel/sched.c - instead of
    open-coding it?

    Ingo
    -
    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: 2007-03-02 14:15    [W:0.024 / U:1.692 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site