• Peter Zijlstra's avatar
    sched/fair: Propagate an effective runnable_load_avg · 1ea6c46a
    Peter Zijlstra authored
    The load balancer uses runnable_load_avg as load indicator. For
    !cgroup this is:
    
      runnable_load_avg = \Sum se->avg.load_avg ; where se->on_rq
    
    That is, a direct sum of all runnable tasks on that runqueue. As
    opposed to load_avg, which is a sum of all tasks on the runqueue,
    which includes a blocked component.
    
    However, in the cgroup case, this comes apart since the group entities
    are always runnable, even if most of their constituent entities are
    blocked.
    
    Therefore introduce a runnable_weight which for task entities is the
    same as the regular weight, but for group entities is a fraction of
    the entity weight and represents the runnable part of the group
    runqueue.
    
    Then propagate this load through the PELT hierarchy to arrive at an
    effective runnable load avgerage -- which we should not confuse with
    the canonical runnable load average.
    Suggested-by: default avatarTejun Heo <tj@kernel.org>
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    1ea6c46a
debug.c 24.6 KB