Messages in this thread Patch in this message | | | From | "Chen, Kenneth W" <> | Subject | [patch 1/2] fix perf. bug in wake-up load balancing for aim7 and db workload | Date | Mon, 13 Feb 2006 19:12:32 -0800 |
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Revert commit d7102e95b7b9c00277562c29aad421d2d521c5f6, which causes more than 10% performance regression with aim7.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
--- linux-2.6.16-rc2/include/linux/sched.h.orig 2006-02-13 18:15:09.660276655 -0800 +++ linux-2.6.16-rc2/include/linux/sched.h 2006-02-13 18:15:36.234495079 -0800 @@ -697,12 +697,9 @@ struct task_struct { int lock_depth; /* BKL lock depth */ -#if defined(CONFIG_SMP) - int last_waker_cpu; /* CPU that last woke this task up */ -#if defined(__ARCH_WANT_UNLOCKED_CTXSW) +#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) int oncpu; #endif -#endif int prio, static_prio; struct list_head run_list; prio_array_t *array; --- linux-2.6.16-rc2/kernel/sched.c.orig 2006-02-13 18:11:28.946412171 -0800 +++ linux-2.6.16-rc2/kernel/sched.c 2006-02-13 18:14:29.595824020 -0800 @@ -1294,9 +1294,6 @@ static int try_to_wake_up(task_t *p, uns } } - if (p->last_waker_cpu != this_cpu) - goto out_set_cpu; - if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed))) goto out_set_cpu; @@ -1367,8 +1364,6 @@ out_set_cpu: cpu = task_cpu(p); } - p->last_waker_cpu = this_cpu; - out_activate: #endif /* CONFIG_SMP */ if (old_state == TASK_UNINTERRUPTIBLE) { @@ -1450,12 +1445,9 @@ void fastcall sched_fork(task_t *p, int #ifdef CONFIG_SCHEDSTATS memset(&p->sched_info, 0, sizeof(p->sched_info)); #endif -#if defined(CONFIG_SMP) - p->last_waker_cpu = cpu; -#if defined(__ARCH_WANT_UNLOCKED_CTXSW) +#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) p->oncpu = 0; #endif -#endif #ifdef CONFIG_PREEMPT /* Want to start with kernel preemption disabled. */ task_thread_info(p)->preempt_count = 1; - 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/
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