Because we may update the execution time (sched_group_set_shares()->
update_cfs_shares()->reweight_entity()->update_curr()) before
reweighting the entity after updating the group shares and this requires
an uptodate version of the runqueue clock. Let's update it on the target
CPU if it runs tickless because scheduler_tick() is not there to maintain
it.
Signed-off-by: Frederic Weisbecker <[email protected]>
Cc: Alessio Igor Bogani <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Chris Metcalf <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Geoff Levand <[email protected]>
Cc: Gilad Ben Yossef <[email protected]>
Cc: Hakan Akkan <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Li Zhong <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
---
kernel/sched/fair.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5eea870..a96f0f2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6068,6 +6068,11 @@ int sched_group_set_shares(struct task_group *tg,
unsigned long shares)
se = tg->se[i];
/* Propagate contribution to hierarchy */
raw_spin_lock_irqsave(&rq->lock, flags);
+ /*
+ * We may call update_curr() which needs an up-to-date
+ * version of rq clock if the CPU runs tickless.
+ */
+ update_nohz_rq_clock(rq);
for_each_sched_entity(se)
update_cfs_shares(group_cfs_rq(se));
raw_spin_unlock_irqrestore(&rq->lock, flags);
--
1.7.5.4
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