Messages in this thread Patch in this message |  | | | From | Frederic Weisbecker <> | | Subject | [PATCH 31/41] sched: Update rq clock on nohz CPU before setting fair group shares | | Date | Tue, 1 May 2012 01:55:05 +0200 |
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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 <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> --- 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 aca16b8..3312abe 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5519,6 +5519,11 @@ 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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