From bd8e7dded88a3e1c085c333f19ff31387616f71a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 5 Apr 2011 17:23:59 +0200 Subject: sched: Remove need_migrate_task() Oleg noticed that need_migrate_task() doesn't need the ->on_cpu check now that ttwu() doesn't do remote enqueues for !->on_rq && ->on_cpu, so remove the helper and replace the single instance with a direct ->on_rq test. Suggested-by: Oleg Nesterov Reviewed-by: Frank Rowand Signed-off-by: Peter Zijlstra Cc: Mike Galbraith Cc: Nick Piggin Cc: Linus Torvalds Cc: Andrew Morton Link: http://lkml.kernel.org/r/20110405152729.556674812@chello.nl Signed-off-by: Ingo Molnar --- kernel/sched.c | 17 +---------------- 1 file changed, 1 insertion(+), 16 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 9e3ede120e81..cd597c7442a3 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2198,21 +2198,6 @@ struct migration_arg { static int migration_cpu_stop(void *data); -/* - * The task's runqueue lock must be held. - * Returns true if you have to wait for migration thread. - */ -static bool need_migrate_task(struct task_struct *p) -{ - /* - * If the task is not on a runqueue (and not running), then - * the next wake-up will properly place the task. - */ - bool running = p->on_rq || p->on_cpu; - smp_rmb(); /* finish_lock_switch() */ - return running; -} - /* * wait_task_inactive - wait for a thread to unschedule. * @@ -5985,7 +5970,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) goto out; dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); - if (need_migrate_task(p)) { + if (p->on_rq) { struct migration_arg arg = { p, dest_cpu }; /* Need help from migration thread: drop lock and wait. */ task_rq_unlock(rq, p, &flags); -- cgit v1.2.3-59-g8ed1b