Drop recursive call to migrate_disabel/enable for local_*lock* api
reported by Steven Rostedt.
local_lock will call migrate_disable via get_local_var - call tree is
get_locked_var
`-> local_lock(lvar)
`-> __local_lock(&get_local_var(lvar));
`--> # define get_local_var(var) (*({
migrate_disable();
&__get_cpu_var(var); })) \
thus there should be no need to call migrate_disable/enable recursively in
spin_try/lock/unlock. This patch addes a spin_trylock_local and replaces
the migration disabling calls by the local calls.
This patch is incomplete as it does not yet cover the _irq/_irqsave variants
by local locks. This patch requires the API cleanup in kernel/softirq.c or
it would break softirq_lock/unlock with respect to migration.
on top of -rt9 with timers-do-not-raise-softirq-unconditionally.patch removed
and API-cleanup-use-local_lock-not-__local_lock-for-soft.patch applied.
Signed-off-by: Nicholas Mc Guire <der.herr@xxxxxxx>
---
include/linux/locallock.h | 8 ++++----
include/linux/spinlock_rt.h | 1 +
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
index e7bd8be..32c684b 100644
--- a/include/linux/locallock.h
+++ b/include/linux/locallock.h
@@ -39,7 +39,7 @@ struct local_irq_lock {
static inline void __local_lock(struct local_irq_lock *lv)
{
if (lv->owner != current) {
- spin_lock(&lv->lock);
+ spin_lock_local(&lv->lock);
LL_WARN(lv->owner);
LL_WARN(lv->nestcnt);
lv->owner = current;
@@ -52,7 +52,7 @@ static inline void __local_lock(struct local_irq_lock *lv)
static inline int __local_trylock(struct local_irq_lock *lv)
{
- if (lv->owner != current && spin_trylock(&lv->lock)) {
+ if (lv->owner != current && spin_trylock_local(&lv->lock)) {
LL_WARN(lv->owner);
LL_WARN(lv->nestcnt);
lv->owner = current;
@@ -79,7 +79,7 @@ static inline void __local_unlock(struct local_irq_lock *lv)
return;
lv->owner = NULL;
- spin_unlock(&lv->lock);
+ spin_unlock_local(&lv->lock);
}
#define local_unlock(lvar) \
@@ -211,7 +211,7 @@ static inline int __local_unlock_irqrestore(struct local_irq_lock *lv,
&__get_cpu_var(var); \
}))
-#define put_locked_var(lvar, var) local_unlock(lvar)
+#define put_locked_var(lvar, var) local_unlock(lvar);
#define local_lock_cpu(lvar) \
({ \
diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h
index b3c504b..4f91114 100644
--- a/include/linux/spinlock_rt.h
+++ b/include/linux/spinlock_rt.h
@@ -37,6 +37,7 @@ extern void __lockfunc __rt_spin_lock(struct rt_mutex *lock);
extern void __lockfunc __rt_spin_unlock(struct rt_mutex *lock);
#define spin_lock_local(lock) rt_spin_lock(lock)
+#define spin_trylock_local(lock) rt_spin_trylock(lock)
#define spin_unlock_local(lock) rt_spin_unlock(lock)
#define spin_lock(lock) \
--
1.7.2.5
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