[tip:sched/core] sched: Update rq clock earlier in unthrottle_cfs_rq

From: tip-bot for Frederic Weisbecker
Date: Tue May 28 2013 - 09:12:42 EST


Commit-ID: 1a55af2e45cce0ff13bc33c8ee99da84e188b615
Gitweb: http://git.kernel.org/tip/1a55af2e45cce0ff13bc33c8ee99da84e188b615
Author: Frederic Weisbecker <fweisbec@xxxxxxxxx>
AuthorDate: Fri, 12 Apr 2013 01:51:01 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 28 May 2013 09:40:25 +0200

sched: Update rq clock earlier in unthrottle_cfs_rq

In this function we are making use of rq->clock right before the
update of the rq clock, let's just call update_rq_clock() just
before that to avoid using a stale rq clock value.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1365724262-20142-5-git-send-email-fweisbec@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/fair.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f76ca21..1c8762a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2319,12 +2319,14 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];

cfs_rq->throttled = 0;
+
+ update_rq_clock(rq);
+
raw_spin_lock(&cfs_b->lock);
cfs_b->throttled_time += rq->clock - cfs_rq->throttled_clock;
list_del_rcu(&cfs_rq->throttled_list);
raw_spin_unlock(&cfs_b->lock);

- update_rq_clock(rq);
/* update hierarchical throttle state */
walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);

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