• Peter Zijlstra's avatar
    sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK · 3e51f33f
    Peter Zijlstra authored
    this replaces the rq->clock stuff (and possibly cpu_clock()).
    
     - architectures that have an 'imperfect' hardware clock can set
       CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
    
     - the 'jiffie' window might be superfulous when we update tick_gtod
       before the __update_sched_clock() call in sched_clock_tick()
    
     - cpu_clock() might be implemented as:
    
         sched_clock_cpu(smp_processor_id())
    
       if the accuracy proves good enough - how far can TSC drift in a
       single jiffie when considering the filtering and idle hooks?
    
    [ mingo@elte.hu: various fixes and cleanups ]
    Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    3e51f33f
sched_clock.c 5.35 KB