From: Ingo Molnar <mingo@elte.hu>
Add lock_need_resched() which is to check for the necessity of lock-break
in a critical section. Used by later latency-break patches.
tested on x86, should work on all architectures.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/include/linux/sched.h | 11 +++++++++++
1 files changed, 11 insertions(+)
diff -puN include/linux/sched.h~add-lock_need_resched include/linux/sched.h
--- 25/include/linux/sched.h~add-lock_need_resched 2004-10-28 01:19:22.035928056 -0700
+++ 25-akpm/include/linux/sched.h 2004-10-28 01:19:22.039927448 -0700
@@ -1050,6 +1050,17 @@ extern int cond_resched_lock(spinlock_t
# define need_lockbreak(lock) 0
#endif
+/*
+ * Does a critical section need to be broken due to another
+ * task waiting or preemption being signalled:
+ */
+static inline int lock_need_resched(spinlock_t *lock)
+{
+ if (need_lockbreak(lock) || need_resched())
+ return 1;
+ return 0;
+}
+
/* Reevaluate whether the task has signals pending delivery.
This is required every time the blocked sigset_t changes.
callers must hold sighand->siglock. */
_