[patch 1/1] sched: update_curr versus correct cfs_rq in check_preempt_wakeup

[Paul Turner]

We update_curr() versus the current entity as the preemption decision is based
on the relative vruntime.  However, update_curr() is not hierarchical and in
the group scheduling case find_matching_se() will have us making the
comparison on a cfs_rq different to the one just updated.

Signed-off-by: Paul Turner <pjt@xxxxxxxxxx>
---
 kernel/sched_fair.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: tip2/kernel/sched_fair.c
===================================================================
--- tip2.orig/kernel/sched_fair.c
+++ tip2/kernel/sched_fair.c
@@ -1919,8 +1919,8 @@ static void check_preempt_wakeup(struct 
 	if (!sched_feat(WAKEUP_PREEMPT))
 		return;
 
-	update_curr(cfs_rq);
 	find_matching_se(&se, &pse);
+	update_curr(cfs_rq_of(se));
 	BUG_ON(!pse);
 	if (wakeup_preempt_entity(se, pse) == 1) {
 		/*


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