* Luiz Capitulino | 2016-05-24 15:15:51 [-0400]:
>Sebastian,
>
>It's not clear to me from our last discussion what's the
>best plan for this patch. I'm sending v2 with the changes
>you suggested.
The patch at the bottom is what I intend to take into the next v4.6-RT.
local_lock_irqsave_on() was already part of the first v4.6 release. I
don't like the part where local_lock_irqsave_on() is a simple
local_irq_safe() on !RT but that is another story.
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
index 493e801e0c9b..845c77f1a5ca 100644
--- a/include/linux/locallock.h
+++ b/include/linux/locallock.h
@@ -66,6 +66,9 @@ static inline void __local_lock(struct local_irq_lock *lv)
#define local_lock(lvar) \
do { __local_lock(&get_local_var(lvar)); } while (0)
+#define local_lock_on(lvar, cpu) \
+ do { __local_lock(&per_cpu(lvar, cpu)); } while (0)
+
static inline int __local_trylock(struct local_irq_lock *lv)
{
if (lv->owner != current && spin_trylock_local(&lv->lock)) {
@@ -104,6 +107,9 @@ static inline void __local_unlock(struct local_irq_lock *lv)
put_local_var(lvar); \
} while (0)
+#define local_unlock_on(lvar, cpu) \
+ do { __local_unlock(&per_cpu(lvar, cpu)); } while (0)
+
static inline void __local_lock_irq(struct local_irq_lock *lv)
{
spin_lock_irqsave(&lv->lock, lv->flags);
diff --git a/mm/swap.c b/mm/swap.c
index 892747266c7e..35fab668a782 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -596,9 +596,9 @@ void lru_add_drain_cpu(int cpu)
unsigned long flags;
/* No harm done if a racing interrupt already did this */
- local_lock_irqsave(rotate_lock, flags);
+ local_lock_irqsave_on(rotate_lock, flags, cpu);
pagevec_move_tail(pvec);
- local_unlock_irqrestore(rotate_lock, flags);
+ local_unlock_irqrestore_on(rotate_lock, flags, cpu);
}
pvec = &per_cpu(lru_deactivate_file_pvecs, cpu);
@@ -666,12 +666,32 @@ void lru_add_drain(void)
local_unlock_cpu(swapvec_lock);
}
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+static inline void remote_lru_add_drain(int cpu, struct cpumask *has_work)
+{
+ local_lock_on(swapvec_lock, cpu);
+ lru_add_drain_cpu(cpu);
+ local_unlock_on(swapvec_lock, cpu);
+}
+
+#else
+
static void lru_add_drain_per_cpu(struct work_struct *dummy)
{
lru_add_drain();
}
static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work);
+static inline void remote_lru_add_drain(int cpu, struct cpumask *has_work)
+{
+ struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
+
+ INIT_WORK(work, lru_add_drain_per_cpu);
+ schedule_work_on(cpu, work);
+ cpumask_set_cpu(cpu, has_work);
+}
+#endif
void lru_add_drain_all(void)
{
@@ -684,21 +704,18 @@ void lru_add_drain_all(void)
cpumask_clear(&has_work);
for_each_online_cpu(cpu) {
- struct work_struct *work = &per_cpu(lru_add_drain_work, cpu);
-
if (pagevec_count(&per_cpu(lru_add_pvec, cpu)) ||
pagevec_count(&per_cpu(lru_rotate_pvecs, cpu)) ||
pagevec_count(&per_cpu(lru_deactivate_file_pvecs, cpu)) ||
pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) ||
- need_activate_page_drain(cpu)) {
- INIT_WORK(work, lru_add_drain_per_cpu);
- schedule_work_on(cpu, work);
- cpumask_set_cpu(cpu, &has_work);
- }
+ need_activate_page_drain(cpu))
+ remote_lru_add_drain(cpu, &has_work);
}
+#ifndef CONFIG_PREEMPT_RT_BASE
for_each_cpu(cpu, &has_work)
flush_work(&per_cpu(lru_add_drain_work, cpu));
+#endif
put_online_cpus();
mutex_unlock(&lock);
--
2.8.1
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