[tip:sched/core] sched: Update rq clock before setting fair group shares

[tip-bot for Frederic Weisbecker <tipbot@zytor.com>]

Commit-ID:  71b1da46ff70309a2ec12ce943aa0d192d2c8f0c
Gitweb:     http://git.kernel.org/tip/71b1da46ff70309a2ec12ce943aa0d192d2c8f0c
Author:     Frederic Weisbecker <fweisbec@gmail.com>
AuthorDate: Fri, 12 Apr 2013 01:50:59 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 28 May 2013 09:40:23 +0200

sched: Update rq clock before setting fair group shares

Because we may update the execution time in

    sched_group_set_shares()->update_cfs_shares()->reweight_entity()->update_curr()

before reweighting the entity while setting the group shares and this requires
an uptodate version of the runqueue clock.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f62b16d..f76ca21 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6107,6 +6107,9 @@ 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);
+
+		/* Possible calls to update_curr() need rq clock */
+		update_rq_clock(rq);
 		for_each_sched_entity(se)
 			update_cfs_shares(group_cfs_rq(se));
 		raw_spin_unlock_irqrestore(&rq->lock, flags);