From: tip-bot for Peter Zijlstra <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, mingo@kernel.org, linux-kernel@vger.kernel.org,
peterz@infradead.org, tglx@linutronix.de
Subject: [tip:sched/hrtimers] sched: Move code around
Date: Thu, 18 Jun 2015 16:02:56 -0700 [thread overview]
Message-ID: <tip-5cc389bcee088b72c8c34a01d596412cab4f3f78@git.kernel.org> (raw)
In-Reply-To: <20150611124743.662086684@infradead.org>
Commit-ID: 5cc389bcee088b72c8c34a01d596412cab4f3f78
Gitweb: http://git.kernel.org/tip/5cc389bcee088b72c8c34a01d596412cab4f3f78
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 11 Jun 2015 14:46:50 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 19 Jun 2015 00:25:26 +0200
sched: Move code around
In preparation to reworking set_cpus_allowed_ptr() move some code
around. This also removes some superfluous #ifdefs and adds comments
to some #endifs.
text data bss dec hex filename
12211532 1738144 1081344 15031020 e55aec defconfig-build/vmlinux.pre
12211532 1738144 1081344 15031020 e55aec defconfig-build/vmlinux.post
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: ktkhai@parallels.com
Cc: rostedt@goodmis.org
Cc: juri.lelli@gmail.com
Cc: pang.xunlei@linaro.org
Cc: oleg@redhat.com
Cc: wanpeng.li@linux.intel.com
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20150611124743.662086684@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/sched/core.c | 364 +++++++++++++++++++++++++---------------------------
1 file changed, 178 insertions(+), 186 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ef546e3..26637c9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1046,6 +1046,180 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
}
#ifdef CONFIG_SMP
+/*
+ * This is how migration works:
+ *
+ * 1) we invoke migration_cpu_stop() on the target CPU using
+ * stop_one_cpu().
+ * 2) stopper starts to run (implicitly forcing the migrated thread
+ * off the CPU)
+ * 3) it checks whether the migrated task is still in the wrong runqueue.
+ * 4) if it's in the wrong runqueue then the migration thread removes
+ * it and puts it into the right queue.
+ * 5) stopper completes and stop_one_cpu() returns and the migration
+ * is done.
+ */
+
+/*
+ * move_queued_task - move a queued task to new rq.
+ *
+ * Returns (locked) new rq. Old rq's lock is released.
+ */
+static struct rq *move_queued_task(struct task_struct *p, int new_cpu)
+{
+ struct rq *rq = task_rq(p);
+
+ lockdep_assert_held(&rq->lock);
+
+ dequeue_task(rq, p, 0);
+ p->on_rq = TASK_ON_RQ_MIGRATING;
+ set_task_cpu(p, new_cpu);
+ raw_spin_unlock(&rq->lock);
+
+ rq = cpu_rq(new_cpu);
+
+ raw_spin_lock(&rq->lock);
+ BUG_ON(task_cpu(p) != new_cpu);
+ p->on_rq = TASK_ON_RQ_QUEUED;
+ enqueue_task(rq, p, 0);
+ check_preempt_curr(rq, p, 0);
+
+ return rq;
+}
+
+struct migration_arg {
+ struct task_struct *task;
+ int dest_cpu;
+};
+
+/*
+ * Move (not current) task off this cpu, onto dest cpu. We're doing
+ * this because either it can't run here any more (set_cpus_allowed()
+ * away from this CPU, or CPU going down), or because we're
+ * attempting to rebalance this task on exec (sched_exec).
+ *
+ * So we race with normal scheduler movements, but that's OK, as long
+ * as the task is no longer on this CPU.
+ *
+ * Returns non-zero if task was successfully migrated.
+ */
+static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
+{
+ struct rq *rq;
+ int ret = 0;
+
+ if (unlikely(!cpu_active(dest_cpu)))
+ return ret;
+
+ rq = cpu_rq(src_cpu);
+
+ raw_spin_lock(&p->pi_lock);
+ raw_spin_lock(&rq->lock);
+ /* Already moved. */
+ if (task_cpu(p) != src_cpu)
+ goto done;
+
+ /* Affinity changed (again). */
+ if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
+ goto fail;
+
+ /*
+ * If we're not on a rq, the next wake-up will ensure we're
+ * placed properly.
+ */
+ if (task_on_rq_queued(p))
+ rq = move_queued_task(p, dest_cpu);
+done:
+ ret = 1;
+fail:
+ raw_spin_unlock(&rq->lock);
+ raw_spin_unlock(&p->pi_lock);
+ return ret;
+}
+
+/*
+ * migration_cpu_stop - this will be executed by a highprio stopper thread
+ * and performs thread migration by bumping thread off CPU then
+ * 'pushing' onto another runqueue.
+ */
+static int migration_cpu_stop(void *data)
+{
+ struct migration_arg *arg = data;
+
+ /*
+ * The original target cpu might have gone down and we might
+ * be on another cpu but it doesn't matter.
+ */
+ local_irq_disable();
+ /*
+ * We need to explicitly wake pending tasks before running
+ * __migrate_task() such that we will not miss enforcing cpus_allowed
+ * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.
+ */
+ sched_ttwu_pending();
+ __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu);
+ local_irq_enable();
+ return 0;
+}
+
+void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
+{
+ if (p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, new_mask);
+
+ cpumask_copy(&p->cpus_allowed, new_mask);
+ p->nr_cpus_allowed = cpumask_weight(new_mask);
+}
+
+/*
+ * Change a given task's CPU affinity. Migrate the thread to a
+ * proper CPU and schedule it away if the CPU it's executing on
+ * is removed from the allowed bitmask.
+ *
+ * NOTE: the caller must have a valid reference to the task, the
+ * task must not exit() & deallocate itself prematurely. The
+ * call is not atomic; no spinlocks may be held.
+ */
+int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
+{
+ unsigned long flags;
+ struct rq *rq;
+ unsigned int dest_cpu;
+ int ret = 0;
+
+ rq = task_rq_lock(p, &flags);
+
+ if (cpumask_equal(&p->cpus_allowed, new_mask))
+ goto out;
+
+ if (!cpumask_intersects(new_mask, cpu_active_mask)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ do_set_cpus_allowed(p, new_mask);
+
+ /* Can the task run on the task's current CPU? If so, we're done */
+ if (cpumask_test_cpu(task_cpu(p), new_mask))
+ goto out;
+
+ dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
+ if (task_running(rq, p) || p->state == TASK_WAKING) {
+ struct migration_arg arg = { p, dest_cpu };
+ /* Need help from migration thread: drop lock and wait. */
+ task_rq_unlock(rq, p, &flags);
+ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
+ tlb_migrate_finish(p->mm);
+ return 0;
+ } else if (task_on_rq_queued(p))
+ rq = move_queued_task(p, dest_cpu);
+out:
+ task_rq_unlock(rq, p, &flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
+
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
#ifdef CONFIG_SCHED_DEBUG
@@ -1186,13 +1360,6 @@ out:
return ret;
}
-struct migration_arg {
- struct task_struct *task;
- int dest_cpu;
-};
-
-static int migration_cpu_stop(void *data);
-
/*
* wait_task_inactive - wait for a thread to unschedule.
*
@@ -1325,9 +1492,7 @@ void kick_process(struct task_struct *p)
preempt_enable();
}
EXPORT_SYMBOL_GPL(kick_process);
-#endif /* CONFIG_SMP */
-#ifdef CONFIG_SMP
/*
* ->cpus_allowed is protected by both rq->lock and p->pi_lock
*/
@@ -1432,7 +1597,7 @@ static void update_avg(u64 *avg, u64 sample)
s64 diff = sample - *avg;
*avg += diff >> 3;
}
-#endif
+#endif /* CONFIG_SMP */
static void
ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
@@ -4773,149 +4938,6 @@ out:
}
#ifdef CONFIG_SMP
-/*
- * move_queued_task - move a queued task to new rq.
- *
- * Returns (locked) new rq. Old rq's lock is released.
- */
-static struct rq *move_queued_task(struct task_struct *p, int new_cpu)
-{
- struct rq *rq = task_rq(p);
-
- lockdep_assert_held(&rq->lock);
-
- dequeue_task(rq, p, 0);
- p->on_rq = TASK_ON_RQ_MIGRATING;
- set_task_cpu(p, new_cpu);
- raw_spin_unlock(&rq->lock);
-
- rq = cpu_rq(new_cpu);
-
- raw_spin_lock(&rq->lock);
- BUG_ON(task_cpu(p) != new_cpu);
- p->on_rq = TASK_ON_RQ_QUEUED;
- enqueue_task(rq, p, 0);
- check_preempt_curr(rq, p, 0);
-
- return rq;
-}
-
-void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
-{
- if (p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, new_mask);
-
- cpumask_copy(&p->cpus_allowed, new_mask);
- p->nr_cpus_allowed = cpumask_weight(new_mask);
-}
-
-/*
- * This is how migration works:
- *
- * 1) we invoke migration_cpu_stop() on the target CPU using
- * stop_one_cpu().
- * 2) stopper starts to run (implicitly forcing the migrated thread
- * off the CPU)
- * 3) it checks whether the migrated task is still in the wrong runqueue.
- * 4) if it's in the wrong runqueue then the migration thread removes
- * it and puts it into the right queue.
- * 5) stopper completes and stop_one_cpu() returns and the migration
- * is done.
- */
-
-/*
- * Change a given task's CPU affinity. Migrate the thread to a
- * proper CPU and schedule it away if the CPU it's executing on
- * is removed from the allowed bitmask.
- *
- * NOTE: the caller must have a valid reference to the task, the
- * task must not exit() & deallocate itself prematurely. The
- * call is not atomic; no spinlocks may be held.
- */
-int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
-{
- unsigned long flags;
- struct rq *rq;
- unsigned int dest_cpu;
- int ret = 0;
-
- rq = task_rq_lock(p, &flags);
-
- if (cpumask_equal(&p->cpus_allowed, new_mask))
- goto out;
-
- if (!cpumask_intersects(new_mask, cpu_active_mask)) {
- ret = -EINVAL;
- goto out;
- }
-
- do_set_cpus_allowed(p, new_mask);
-
- /* Can the task run on the task's current CPU? If so, we're done */
- if (cpumask_test_cpu(task_cpu(p), new_mask))
- goto out;
-
- dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
- if (task_running(rq, p) || p->state == TASK_WAKING) {
- struct migration_arg arg = { p, dest_cpu };
- /* Need help from migration thread: drop lock and wait. */
- task_rq_unlock(rq, p, &flags);
- stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
- tlb_migrate_finish(p->mm);
- return 0;
- } else if (task_on_rq_queued(p))
- rq = move_queued_task(p, dest_cpu);
-out:
- task_rq_unlock(rq, p, &flags);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
-
-/*
- * Move (not current) task off this cpu, onto dest cpu. We're doing
- * this because either it can't run here any more (set_cpus_allowed()
- * away from this CPU, or CPU going down), or because we're
- * attempting to rebalance this task on exec (sched_exec).
- *
- * So we race with normal scheduler movements, but that's OK, as long
- * as the task is no longer on this CPU.
- *
- * Returns non-zero if task was successfully migrated.
- */
-static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
-{
- struct rq *rq;
- int ret = 0;
-
- if (unlikely(!cpu_active(dest_cpu)))
- return ret;
-
- rq = cpu_rq(src_cpu);
-
- raw_spin_lock(&p->pi_lock);
- raw_spin_lock(&rq->lock);
- /* Already moved. */
- if (task_cpu(p) != src_cpu)
- goto done;
-
- /* Affinity changed (again). */
- if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
- goto fail;
-
- /*
- * If we're not on a rq, the next wake-up will ensure we're
- * placed properly.
- */
- if (task_on_rq_queued(p))
- rq = move_queued_task(p, dest_cpu);
-done:
- ret = 1;
-fail:
- raw_spin_unlock(&rq->lock);
- raw_spin_unlock(&p->pi_lock);
- return ret;
-}
#ifdef CONFIG_NUMA_BALANCING
/* Migrate current task p to target_cpu */
@@ -4963,35 +4985,9 @@ void sched_setnuma(struct task_struct *p, int nid)
enqueue_task(rq, p, 0);
task_rq_unlock(rq, p, &flags);
}
-#endif
-
-/*
- * migration_cpu_stop - this will be executed by a highprio stopper thread
- * and performs thread migration by bumping thread off CPU then
- * 'pushing' onto another runqueue.
- */
-static int migration_cpu_stop(void *data)
-{
- struct migration_arg *arg = data;
-
- /*
- * The original target cpu might have gone down and we might
- * be on another cpu but it doesn't matter.
- */
- local_irq_disable();
- /*
- * We need to explicitly wake pending tasks before running
- * __migrate_task() such that we will not miss enforcing cpus_allowed
- * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test.
- */
- sched_ttwu_pending();
- __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu);
- local_irq_enable();
- return 0;
-}
+#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_HOTPLUG_CPU
-
/*
* Ensures that the idle task is using init_mm right before its cpu goes
* offline.
@@ -5094,7 +5090,6 @@ static void migrate_tasks(unsigned int dead_cpu)
rq->stop = stop;
}
-
#endif /* CONFIG_HOTPLUG_CPU */
#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
@@ -5273,7 +5268,7 @@ static void register_sched_domain_sysctl(void)
static void unregister_sched_domain_sysctl(void)
{
}
-#endif
+#endif /* CONFIG_SCHED_DEBUG && CONFIG_SYSCTL */
static void set_rq_online(struct rq *rq)
{
@@ -5420,9 +5415,6 @@ static int __init migration_init(void)
return 0;
}
early_initcall(migration_init);
-#endif
-
-#ifdef CONFIG_SMP
static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */
@@ -6648,7 +6640,7 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
struct sched_group *sg;
struct sched_group_capacity *sgc;
- sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
+ sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
GFP_KERNEL, cpu_to_node(j));
if (!sd)
return -ENOMEM;
next prev parent reply other threads:[~2015-06-18 23:03 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-11 12:46 [PATCH 00/18] sched: balance callbacks v4 Peter Zijlstra
2015-06-11 12:46 ` [PATCH 01/18] sched: Replace post_schedule with a balance callback list Peter Zijlstra
2015-06-11 15:32 ` Kirill Tkhai
2015-06-18 23:00 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 02/18] sched: Use replace normalize_task() with __sched_setscheduler() Peter Zijlstra
2015-06-18 23:00 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 03/18] sched: Allow balance callbacks for check_class_changed() Peter Zijlstra
2015-06-18 23:01 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 04/18] sched,rt: Remove return value from pull_rt_task() Peter Zijlstra
2015-06-18 23:01 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 05/18] sched,rt: Convert switched_{from,to}_rt() / prio_changed_rt() to balance callbacks Peter Zijlstra
2015-06-18 23:01 ` [tip:sched/hrtimers] sched, rt: Convert switched_{from, to}_rt() " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 06/18] sched,dl: Remove return value from pull_dl_task() Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 07/18] sched,dl: Convert switched_{from,to}_dl() / prio_changed_dl() to balance callbacks Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] sched, dl: Convert switched_{from, to}_dl() " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 08/18] hrtimer: Remove HRTIMER_STATE_MIGRATE Peter Zijlstra
2015-06-18 22:18 ` [tip:timers/core] " tip-bot for Oleg Nesterov
2015-06-11 12:46 ` [PATCH 09/18] hrtimer: Fix hrtimer_is_queued() hole Peter Zijlstra
2015-06-18 22:18 ` [tip:timers/core] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 10/18] seqcount: Rename write_seqcount_barrier() Peter Zijlstra
2015-06-18 22:19 ` [tip:timers/core] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 11/18] seqcount: Introduce raw_write_seqcount_barrier() Peter Zijlstra
2015-06-11 15:33 ` Paul E. McKenney
2015-06-11 21:45 ` Paul E. McKenney
2015-06-12 7:08 ` Peter Zijlstra
2015-06-12 18:59 ` Oleg Nesterov
2015-06-17 12:29 ` Peter Zijlstra
2015-06-17 14:57 ` Paul E. McKenney
2015-06-17 15:11 ` Peter Zijlstra
2015-06-17 15:42 ` Paul E. McKenney
2015-06-17 16:58 ` Peter Zijlstra
2015-06-17 15:49 ` Peter Zijlstra
2015-06-17 16:37 ` Paul E. McKenney
2015-06-17 17:11 ` Peter Zijlstra
2015-06-17 18:02 ` Paul E. McKenney
2015-06-18 9:15 ` Peter Zijlstra
2015-06-18 9:40 ` Ingo Molnar
2015-06-18 10:40 ` Peter Zijlstra
2015-06-18 16:54 ` Paul E. McKenney
2015-06-18 17:10 ` Steven Rostedt
2015-06-18 17:51 ` Paul E. McKenney
2015-06-18 22:19 ` [tip:timers/core] seqcount: Introduce raw_write_seqcount_barrier( ) tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 12/18] hrtimer: Allow hrtimer::function() to free the timer Peter Zijlstra
2015-06-18 22:19 ` [tip:timers/core] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 13/18] sched,dl: Fix sched class hopping CBS hole Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 14/18] sched: Move code around Peter Zijlstra
2015-06-18 23:02 ` tip-bot for Peter Zijlstra [this message]
2015-06-11 12:46 ` [PATCH 15/18] sched: Streamline the task migration locking a little Peter Zijlstra
2015-06-18 23:03 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 16/18] lockdep: Simplify lock_release() Peter Zijlstra
2015-06-18 23:03 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 17/18] lockdep: Implement lock pinning Peter Zijlstra
2015-06-18 23:03 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 18/18] sched,lockdep: Employ " Peter Zijlstra
2015-06-18 23:04 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-12-29 5:41 ` [PATCH 00/18] sched: balance callbacks v4 Byungchul Park
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tip-5cc389bcee088b72c8c34a01d596412cab4f3f78@git.kernel.org \
--to=tipbot@zytor.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.