Commit-ID: 536bd00cdbb7b908573e5a93bae67b64cbae60d8
Gitweb: http://git.kernel.org/tip/536bd00cdbb7b908573e5a93bae67b64cbae60d8
Author: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
AuthorDate: Fri, 6 May 2016 14:58:43 +0200
Committer: Ingo Molnar <mi...@kernel.org>
CommitDate: Sat, 7 May 2016 07:45:34 +0200
sched/fair: Fix !CONFIG_SMP kernel cpufreq governor breakage
The following commit:
34e2c555f3e1 ("cpufreq: Add mechanism for registering utilization update
callbacks")
overlooked the fact that update_load_avg(), where CFS invokes cpufreq
utilization update callbacks, becomes an empty stub on UP kernels.
In consequence, if !CONFIG_SMP, cpufreq governors are never invoked
from CFS and they do not have a chance to evaluate CPU performace
levels and update them often enough.
Needless to say, things don't work as expected then.
Fix the problem by making the !CONFIG_SMP stub of update_load_avg()
invoke cpufreq update callbacks too.
Reported-by: Steve Muckle <steve.muc...@linaro.org>
Tested-by: Steve Muckle <steve.muc...@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Acked-by: Steve Muckle <steve.muc...@linaro.org>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Linux PM list <linux...@vger.kernel.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Viresh Kumar <viresh.ku...@linaro.org>
Fixes: 34e2c555f3e1 (cpufreq: Add mechanism for registering utilization update
callbacks)
Link: http://lkml.kernel.org/r/6282396.vvedgvy...@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
kernel/sched/fair.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0fe30e6..40748dc 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3030,7 +3030,14 @@ static int idle_balance(struct rq *this_rq);
#else /* CONFIG_SMP */
-static inline void update_load_avg(struct sched_entity *se, int update_tg) {}
+static inline void update_load_avg(struct sched_entity *se, int not_used)
+{
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ struct rq *rq = rq_of(cfs_rq);
+
+ cpufreq_trigger_update(rq_clock(rq));
+}
+
static inline void
enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
static inline void
