[rt-patch 2/3] sched: Introduce raw_cond_resched_lock()

[Mike Galbraith]

Add raw_cond_resched_lock() infrastructure.

Signed-off-by: Mike Galbraith <efa...@gmx.de>
---
 include/linux/sched.h |   15 +++++++++++++++
 kernel/sched/core.c   |   20 ++++++++++++++++++++
 2 files changed, 35 insertions(+)

--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1779,12 +1779,18 @@ static inline int _cond_resched(void) {
 })
 
 extern int __cond_resched_lock(spinlock_t *lock);
+extern int __raw_cond_resched_lock(raw_spinlock_t *lock);
 
 #define cond_resched_lock(lock) ({                             \
        ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
        __cond_resched_lock(lock);                              \
 })
 
+#define raw_cond_resched_lock(lock) ({                         \
+       ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
+       __raw_cond_resched_lock(lock);                          \
+})
+
 #ifndef CONFIG_PREEMPT_RT_FULL
 extern int __cond_resched_softirq(void);
 
@@ -1817,6 +1823,15 @@ static inline int spin_needbreak(spinloc
 #else
        return 0;
 #endif
+}
+
+static inline int raw_spin_needbreak(raw_spinlock_t *lock)
+{
+#ifdef CONFIG_PREEMPT
+       return raw_spin_is_contended(lock);
+#else
+       return 0;
+#endif
 }
 
 static __always_inline bool need_resched(void)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5065,6 +5065,26 @@ int __cond_resched_lock(spinlock_t *lock
 }
 EXPORT_SYMBOL(__cond_resched_lock);
 
+int __raw_cond_resched_lock(raw_spinlock_t *lock)
+{
+       int resched = should_resched(PREEMPT_LOCK_OFFSET);
+       int ret = 0;
+
+       lockdep_assert_held(lock);
+
+       if (raw_spin_needbreak(lock) || resched) {
+               raw_spin_unlock(lock);
+               if (resched)
+                       preempt_schedule_common();
+               else
+                       cpu_relax();
+               ret = 1;
+               raw_spin_lock(lock);
+       }
+       return ret;
+}
+EXPORT_SYMBOL(__raw_cond_resched_lock);
+
 #ifndef CONFIG_PREEMPT_RT_FULL
 int __sched __cond_resched_softirq(void)
 {