From mboxrd@z Thu Jan 1 00:00:00 1970 From: "tip-bot for Rafael J. Wysocki" Subject: [tip:sched/urgent] sched/fair: Fix !CONFIG_SMP kernel cpufreq governor breakage Date: Fri, 6 May 2016 23:37:46 -0700 Message-ID: References: <6282396.VVEdgVYxO3@vostro.rjw.lan> Reply-To: rafael.j.wysocki@intel.com, mingo@kernel.org, linux-pm@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, torvalds@linux-foundation.org, viresh.kumar@linaro.org, srinivas.pandruvada@linux.intel.com, steve.muckle@linaro.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <6282396.VVEdgVYxO3@vostro.rjw.lan> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: linux-tip-commits@vger.kernel.org Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, rafael.j.wysocki@intel.com, tglx@linutronix.de, linux-pm@vger.kernel.org, steve.muckle@linaro.org, srinivas.pandruvada@linux.intel.com, torvalds@linux-foundation.org, viresh.kumar@linaro.org List-Id: linux-pm@vger.kernel.org Commit-ID: 536bd00cdbb7b908573e5a93bae67b64cbae60d8 Gitweb: http://git.kernel.org/tip/536bd00cdbb7b908573e5a93bae67b64cbae60d8 Author: Rafael J. Wysocki AuthorDate: Fri, 6 May 2016 14:58:43 +0200 Committer: Ingo Molnar 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 Tested-by: Steve Muckle Signed-off-by: Rafael J. Wysocki Acked-by: Steve Muckle Cc: Linus Torvalds Cc: Linux PM list Cc: Peter Zijlstra Cc: Srinivas Pandruvada Cc: Thomas Gleixner Cc: Viresh Kumar Fixes: 34e2c555f3e1 (cpufreq: Add mechanism for registering utilization update callbacks) Link: http://lkml.kernel.org/r/6282396.VVEdgVYxO3@vostro.rjw.lan Signed-off-by: Ingo Molnar --- 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