From: Linus Torvalds Date: Tue, 18 May 2010 15:27:54 +0000 (-0700) Subject: Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel... X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b8ae30ee26d379db436b0b8c8c3ff1b52f69e5d1;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git Merge branch 'sched-core-for-linus' of git://git./linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits) stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback() sched, wait: Use wrapper functions sched: Remove a stale comment ondemand: Make the iowait-is-busy time a sysfs tunable ondemand: Solve a big performance issue by counting IOWAIT time as busy sched: Intoduce get_cpu_iowait_time_us() sched: Eliminate the ts->idle_lastupdate field sched: Fold updating of the last_update_time_info into update_ts_time_stats() sched: Update the idle statistics in get_cpu_idle_time_us() sched: Introduce a function to update the idle statistics sched: Add a comment to get_cpu_idle_time_us() cpu_stop: add dummy implementation for UP sched: Remove rq argument to the tracepoints rcu: need barrier() in UP synchronize_sched_expedited() sched: correctly place paranioa memory barriers in synchronize_sched_expedited() sched: kill paranoia check in synchronize_sched_expedited() sched: replace migration_thread with cpu_stop stop_machine: reimplement using cpu_stop cpu_stop: implement stop_cpu[s]() sched: Fix select_idle_sibling() logic in select_task_rq_fair() ... --- b8ae30ee26d379db436b0b8c8c3ff1b52f69e5d1 diff --cc include/linux/rcutree.h index 48282055e83d,24e467e526b8..c0ed1c056f29 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@@ -34,9 -34,7 +34,8 @@@ struct notifier_block extern void rcu_sched_qs(int cpu); extern void rcu_bh_qs(int cpu); +extern void rcu_note_context_switch(int cpu); extern int rcu_needs_cpu(int cpu); - extern int rcu_expedited_torture_stats(char *page); #ifdef CONFIG_TREE_PREEMPT_RCU diff --cc kernel/sched.c index 5cd607ec8405,b531d7934083..1d93cd0ae4d3 --- a/kernel/sched.c +++ b/kernel/sched.c @@@ -2076,17 -2054,52 +2064,9 @@@ static bool migrate_task(struct task_st * If the task is not on a runqueue (and not running), then * the next wake-up will properly place the task. */ - if (!p->se.on_rq && !task_running(rq, p)) - return 0; - - init_completion(&req->done); - req->task = p; - req->dest_cpu = dest_cpu; - list_add(&req->list, &rq->migration_queue); - - return 1; + return p->se.on_rq || task_running(rq, p); } -/* - * wait_task_context_switch - wait for a thread to complete at least one - * context switch. - * - * @p must not be current. - */ -void wait_task_context_switch(struct task_struct *p) -{ - unsigned long nvcsw, nivcsw, flags; - int running; - struct rq *rq; - - nvcsw = p->nvcsw; - nivcsw = p->nivcsw; - for (;;) { - /* - * The runqueue is assigned before the actual context - * switch. We need to take the runqueue lock. - * - * We could check initially without the lock but it is - * very likely that we need to take the lock in every - * iteration. - */ - rq = task_rq_lock(p, &flags); - running = task_running(rq, p); - task_rq_unlock(rq, &flags); - - if (likely(!running)) - break; - /* - * The switch count is incremented before the actual - * context switch. We thus wait for two switches to be - * sure at least one completed. - */ - if ((p->nvcsw - nvcsw) > 1) - break; - if ((p->nivcsw - nivcsw) > 1) - break; - - cpu_relax(); - } -} - /* * wait_task_inactive - wait for a thread to unschedule. *