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    sched/fair: Make select_idle_cpu() more aggressive · 4c77b18c
    Peter Zijlstra 提交于
    Kitsunyan reported desktop latency issues on his Celeron 887 because
    of commit:
    
      1b568f0a ("sched/core: Optimize SCHED_SMT")
    
    ... even though his CPU doesn't do SMT.
    
    The effect of running the SMT code on a !SMT part is basically a more
    aggressive select_idle_cpu(). Removing the avg condition fixed things
    for him.
    
    I also know FB likes this test gone, even though other workloads like
    having it.
    
    For now, take it out by default, until we get a better idea.
    Reported-by: Nkitsunyan <kitsunyan@inbox.ru>
    Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
    Cc: Chris Mason <clm@fb.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Mike Galbraith <efault@gmx.de>
    Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-kernel@vger.kernel.org
    Signed-off-by: NIngo Molnar <mingo@kernel.org>
    4c77b18c
fair.c 248.5 KB