X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fsched.c;fp=kernel%2Fsched.c;h=026ba1f6c7cb67cb609727da598bee1ae5f4d3a6;hb=4e76c8a9fa413ccc09d3f7f664183dcce3555d57;hp=60bff8bec9f36a141f4335eb6e3547c18ea35aa7;hpb=1db395853d4f30d6120458bd279ede1f882a8525;p=linux-2.6.git

diff --git a/kernel/sched.c b/kernel/sched.c
index 60bff8bec..026ba1f6c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4189,17 +4189,22 @@ asmlinkage long sys_sched_yield(void)
 	return 0;
 }
 
-static inline void __cond_resched(void)
+static inline int __resched_legal(int expected_preempt_count)
+{
+	if (unlikely(preempt_count() != expected_preempt_count))
+		return 0;
+	if (unlikely(system_state != SYSTEM_RUNNING))
+		return 0;
+	return 1;
+}
+
+static void __cond_resched(void)
 {
 	/*
 	 * The BKS might be reacquired before we have dropped
 	 * PREEMPT_ACTIVE, which could trigger a second
 	 * cond_resched() call.
 	 */
-	if (unlikely(preempt_count()))
-		return;
-	if (unlikely(system_state != SYSTEM_RUNNING))
-		return;
 	do {
 		add_preempt_count(PREEMPT_ACTIVE);
 		schedule();
@@ -4209,13 +4214,12 @@ static inline void __cond_resched(void)
 
 int __sched cond_resched(void)
 {
-	if (need_resched()) {
+	if (need_resched() && __resched_legal(0)) {
 		__cond_resched();
 		return 1;
 	}
 	return 0;
 }
-
 EXPORT_SYMBOL(cond_resched);
 
 /*
@@ -4236,7 +4240,7 @@ int cond_resched_lock(spinlock_t *lock)
 		ret = 1;
 		spin_lock(lock);
 	}
-	if (need_resched()) {
+	if (need_resched() && __resched_legal(1)) {
 		_raw_spin_unlock(lock);
 		preempt_enable_no_resched();
 		__cond_resched();
@@ -4245,14 +4249,13 @@ int cond_resched_lock(spinlock_t *lock)
 	}
 	return ret;
 }
-
 EXPORT_SYMBOL(cond_resched_lock);
 
 int __sched cond_resched_softirq(void)
 {
 	BUG_ON(!in_softirq());
 
-	if (need_resched()) {
+	if (need_resched() && __resched_legal(0)) {
 		__local_bh_enable();
 		__cond_resched();
 		local_bh_disable();
@@ -4260,10 +4263,8 @@ int __sched cond_resched_softirq(void)
 	}
 	return 0;
 }
-
 EXPORT_SYMBOL(cond_resched_softirq);
 
-
 /**
  * yield - yield the current processor to other threads.
  *