sched: Move periodic share updates to entity_tick()
Long running entities that do not block (dequeue) require periodic updates to
maintain accurate share values. (Note: group entities with several threads are
quite likely to be non-blocking in many circumstances).
By virtue of being long-running however, we will see entity ticks (otherwise
the required update occurs in dequeue/put and we are done). Thus we can move
the detection (and associated work) for these updates into the periodic path.
This restores the 'atomicity' of update_curr() with respect to accounting.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101216031038.067028969@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index c886717..16ee398 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -564,10 +564,6 @@
#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
cfs_rq->load_unacc_exec_time += delta_exec;
- if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
- update_cfs_load(cfs_rq, 0);
- update_cfs_shares(cfs_rq, 0);
- }
#endif
}
@@ -809,6 +805,14 @@
reweight_entity(cfs_rq_of(se), se, shares);
}
+
+static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+ if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
+ update_cfs_load(cfs_rq, 0);
+ update_cfs_shares(cfs_rq, 0);
+ }
+}
#else /* CONFIG_FAIR_GROUP_SCHED */
static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
{
@@ -817,6 +821,10 @@
static inline void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta)
{
}
+
+static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+}
#endif /* CONFIG_FAIR_GROUP_SCHED */
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -1133,6 +1141,11 @@
*/
update_curr(cfs_rq);
+ /*
+ * Update share accounting for long-running entities.
+ */
+ update_entity_shares_tick(cfs_rq);
+
#ifdef CONFIG_SCHED_HRTICK
/*
* queued ticks are scheduled to match the slice, so don't bother