193 lines
5.2 KiB
Diff
193 lines
5.2 KiB
Diff
Subject: sched-migrate-disable.patch
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Thu, 16 Jun 2011 13:26:08 +0200
|
|
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
---
|
|
include/linux/preempt.h | 8 ++++
|
|
include/linux/sched.h | 13 +++++--
|
|
kernel/sched/core.c | 88 +++++++++++++++++++++++++++++++++++++++++++++---
|
|
lib/smp_processor_id.c | 6 +--
|
|
4 files changed, 104 insertions(+), 11 deletions(-)
|
|
|
|
--- a/include/linux/preempt.h
|
|
+++ b/include/linux/preempt.h
|
|
@@ -114,6 +114,14 @@ do { \
|
|
|
|
#endif /* CONFIG_PREEMPT_COUNT */
|
|
|
|
+#ifdef CONFIG_SMP
|
|
+extern void migrate_disable(void);
|
|
+extern void migrate_enable(void);
|
|
+#else
|
|
+# define migrate_disable() barrier()
|
|
+# define migrate_enable() barrier()
|
|
+#endif
|
|
+
|
|
#ifdef CONFIG_PREEMPT_RT_FULL
|
|
# define preempt_disable_rt() preempt_disable()
|
|
# define preempt_enable_rt() preempt_enable()
|
|
--- a/include/linux/sched.h
|
|
+++ b/include/linux/sched.h
|
|
@@ -1280,6 +1280,7 @@ struct task_struct {
|
|
#endif
|
|
|
|
unsigned int policy;
|
|
+ int migrate_disable;
|
|
int nr_cpus_allowed;
|
|
cpumask_t cpus_allowed;
|
|
|
|
@@ -1631,9 +1632,6 @@ struct task_struct {
|
|
#endif
|
|
};
|
|
|
|
-/* Future-safe accessor for struct task_struct's cpus_allowed. */
|
|
-#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
|
|
-
|
|
#ifdef CONFIG_NUMA_BALANCING
|
|
extern void task_numa_fault(int node, int pages, bool migrated);
|
|
extern void set_numabalancing_state(bool enabled);
|
|
@@ -2813,6 +2811,15 @@ static inline void set_task_cpu(struct t
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
+/* Future-safe accessor for struct task_struct's cpus_allowed. */
|
|
+static inline const struct cpumask *tsk_cpus_allowed(struct task_struct *p)
|
|
+{
|
|
+ if (p->migrate_disable)
|
|
+ return cpumask_of(task_cpu(p));
|
|
+
|
|
+ return &p->cpus_allowed;
|
|
+}
|
|
+
|
|
extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
|
|
extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
|
|
|
|
--- a/kernel/sched/core.c
|
|
+++ b/kernel/sched/core.c
|
|
@@ -4738,11 +4738,12 @@ void __cpuinit init_idle(struct task_str
|
|
#ifdef CONFIG_SMP
|
|
void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
|
|
{
|
|
- if (p->sched_class && p->sched_class->set_cpus_allowed)
|
|
- p->sched_class->set_cpus_allowed(p, new_mask);
|
|
-
|
|
+ if (!p->migrate_disable) {
|
|
+ if (p->sched_class && p->sched_class->set_cpus_allowed)
|
|
+ p->sched_class->set_cpus_allowed(p, new_mask);
|
|
+ p->nr_cpus_allowed = cpumask_weight(new_mask);
|
|
+ }
|
|
cpumask_copy(&p->cpus_allowed, new_mask);
|
|
- p->nr_cpus_allowed = cpumask_weight(new_mask);
|
|
}
|
|
|
|
/*
|
|
@@ -4793,7 +4794,7 @@ int set_cpus_allowed_ptr(struct task_str
|
|
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))
|
|
+ if (cpumask_test_cpu(task_cpu(p), new_mask) || p->migrate_disable)
|
|
goto out;
|
|
|
|
dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
|
|
@@ -4812,6 +4813,83 @@ out:
|
|
}
|
|
EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
|
|
|
|
+void migrate_disable(void)
|
|
+{
|
|
+ struct task_struct *p = current;
|
|
+ const struct cpumask *mask;
|
|
+ unsigned long flags;
|
|
+ struct rq *rq;
|
|
+
|
|
+ preempt_disable();
|
|
+ if (p->migrate_disable) {
|
|
+ p->migrate_disable++;
|
|
+ preempt_enable();
|
|
+ return;
|
|
+ }
|
|
+
|
|
+ pin_current_cpu();
|
|
+ if (unlikely(!scheduler_running)) {
|
|
+ p->migrate_disable = 1;
|
|
+ preempt_enable();
|
|
+ return;
|
|
+ }
|
|
+ rq = task_rq_lock(p, &flags);
|
|
+ p->migrate_disable = 1;
|
|
+ mask = tsk_cpus_allowed(p);
|
|
+
|
|
+ WARN_ON(!cpumask_test_cpu(smp_processor_id(), mask));
|
|
+
|
|
+ if (!cpumask_equal(&p->cpus_allowed, mask)) {
|
|
+ if (p->sched_class->set_cpus_allowed)
|
|
+ p->sched_class->set_cpus_allowed(p, mask);
|
|
+ p->nr_cpus_allowed = cpumask_weight(mask);
|
|
+ }
|
|
+ task_rq_unlock(rq, p, &flags);
|
|
+ preempt_enable();
|
|
+}
|
|
+EXPORT_SYMBOL(migrate_disable);
|
|
+
|
|
+void migrate_enable(void)
|
|
+{
|
|
+ struct task_struct *p = current;
|
|
+ const struct cpumask *mask;
|
|
+ unsigned long flags;
|
|
+ struct rq *rq;
|
|
+
|
|
+ WARN_ON_ONCE(p->migrate_disable <= 0);
|
|
+
|
|
+ preempt_disable();
|
|
+ if (p->migrate_disable > 1) {
|
|
+ p->migrate_disable--;
|
|
+ preempt_enable();
|
|
+ return;
|
|
+ }
|
|
+
|
|
+ if (unlikely(!scheduler_running)) {
|
|
+ p->migrate_disable = 0;
|
|
+ unpin_current_cpu();
|
|
+ preempt_enable();
|
|
+ return;
|
|
+ }
|
|
+
|
|
+ rq = task_rq_lock(p, &flags);
|
|
+ p->migrate_disable = 0;
|
|
+ mask = tsk_cpus_allowed(p);
|
|
+
|
|
+ WARN_ON(!cpumask_test_cpu(smp_processor_id(), mask));
|
|
+
|
|
+ if (!cpumask_equal(&p->cpus_allowed, mask)) {
|
|
+ if (p->sched_class->set_cpus_allowed)
|
|
+ p->sched_class->set_cpus_allowed(p, mask);
|
|
+ p->nr_cpus_allowed = cpumask_weight(mask);
|
|
+ }
|
|
+
|
|
+ task_rq_unlock(rq, p, &flags);
|
|
+ unpin_current_cpu();
|
|
+ preempt_enable();
|
|
+}
|
|
+EXPORT_SYMBOL(migrate_enable);
|
|
+
|
|
/*
|
|
* 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()
|
|
--- a/lib/smp_processor_id.c
|
|
+++ b/lib/smp_processor_id.c
|
|
@@ -39,9 +39,9 @@ notrace unsigned int debug_smp_processor
|
|
if (!printk_ratelimit())
|
|
goto out_enable;
|
|
|
|
- printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
|
|
- "code: %s/%d\n",
|
|
- preempt_count() - 1, current->comm, current->pid);
|
|
+ printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x %08x] "
|
|
+ "code: %s/%d\n", preempt_count() - 1,
|
|
+ current->migrate_disable, current->comm, current->pid);
|
|
print_symbol("caller is %s\n", (long)__builtin_return_address(0));
|
|
dump_stack();
|
|
|