diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2011-06-06 10:20:33 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2015-02-13 22:20:32 (GMT) |
| commit | a2dc3dc8baee709966e36929b6fbd1cb141cdc0a (patch) | |
| tree | 2b8fb288ca53ac67e0c67b55afb50d0a3ad1e791 /kernel/sched | |
| parent | 7cb4692689e70d12daa08b31634f29107020d0a1 (diff) | |
| download | linux-fsl-qoriq-a2dc3dc8baee709966e36929b6fbd1cb141cdc0a.tar.xz | |
sched-mmdrop-delayed.patch
Needs thread context (pgd_lock) -> ifdeffed. workqueues wont work with
RT
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f382e71..e45a599 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1905,8 +1905,12 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) finish_arch_post_lock_switch(); fire_sched_in_preempt_notifiers(current); + /* + * We use mmdrop_delayed() here so we don't have to do the + * full __mmdrop() when we are the last user. + */ if (mm) - mmdrop(mm); + mmdrop_delayed(mm); if (unlikely(prev_state == TASK_DEAD)) { /* * Remove function-return probe instances associated with this @@ -4437,6 +4441,8 @@ static int migration_cpu_stop(void *data) #ifdef CONFIG_HOTPLUG_CPU +static DEFINE_PER_CPU(struct mm_struct *, idle_last_mm); + /* * Ensures that the idle task is using init_mm right before its cpu goes * offline. @@ -4449,7 +4455,12 @@ void idle_task_exit(void) if (mm != &init_mm) switch_mm(mm, &init_mm, current); - mmdrop(mm); + + /* + * Defer the cleanup to an alive cpu. On RT we can neither + * call mmdrop() nor mmdrop_delayed() from here. + */ + per_cpu(idle_last_mm, smp_processor_id()) = mm; } /* @@ -4773,6 +4784,10 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DEAD: calc_load_migrate(rq); + if (per_cpu(idle_last_mm, cpu)) { + mmdrop(per_cpu(idle_last_mm, cpu)); + per_cpu(idle_last_mm, cpu) = NULL; + } break; #endif } |