[PATCH] sched: add schedstat_set() API

add the schedstat_set() API, to allow the reduction of
CONFIG_SCHEDSTAT related #ifdefs. No code changed.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/sched_stats.h

@@ -116,6 +116,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
 }
 # define schedstat_inc(rq, field)	do { (rq)->field++; } while (0)
 # define schedstat_add(rq, field, amt)	do { (rq)->field += (amt); } while (0)
+# define schedstat_set(var, val)	do { var = (val); } while (0)
 #else /* !CONFIG_SCHEDSTATS */
 static inline void
 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
@@ -125,6 +126,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
 {}
 # define schedstat_inc(rq, field)	do { } while (0)
 # define schedstat_add(rq, field, amt)	do { } while (0)
+# define schedstat_set(var, val)	do { } while (0)
 #endif
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)