From f5b4e661c15486616c73eafb739337c7a6e46427 Mon Sep 17 00:00:00 2001 From: Lianwei Wang Date: Thu, 1 Nov 2012 09:59:52 +0800 Subject: [PATCH] cpufreq: interactive: use deferrable timer by default Avoid wakeups only to handle the governor timer when the system is otherwise idle. For platforms where the power cost of remaining in idle at higher CPU speed may outweigh the cost of a governor wakeup from idle to lower the speed, set parameter cpufreq_interactive.governidle=1. Change-Id: Id6c43eb35caecf9b0574fcdd5b769711bc7e6de6 Signed-off-by: LianWei WANG Signed-off-by: Todd Poynor --- drivers/cpufreq/cpufreq_interactive.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c index e53eae221499..71887cabfadb 100644 --- a/drivers/cpufreq/cpufreq_interactive.c +++ b/drivers/cpufreq/cpufreq_interactive.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -92,6 +93,11 @@ static unsigned long above_hispeed_delay_val; static int boost_val; +static bool governidle; +module_param(governidle, bool, S_IWUSR | S_IRUGO); +MODULE_PARM_DESC(governidle, + "Set to 1 to wake up CPUs from idle to reduce speed (default 0)"); + static int cpufreq_governor_interactive(struct cpufreq_policy *policy, unsigned int event); @@ -240,10 +246,11 @@ rearm_if_notmax: rearm: if (!timer_pending(&pcpu->cpu_timer)) { /* - * If already at min, cancel the timer if that CPU goes idle. - * We don't need to re-evaluate speed until the next idle exit. + * If governing speed in idle and already at min, cancel the + * timer if that CPU goes idle. We don't need to re-evaluate + * speed until the next idle exit. */ - if (pcpu->target_freq == pcpu->policy->min) + if (governidle && pcpu->target_freq == pcpu->policy->min) pcpu->timer_idlecancel = 1; pcpu->time_in_idle = get_cpu_idle_time_us( @@ -268,7 +275,6 @@ static void cpufreq_interactive_idle_start(void) pending = timer_pending(&pcpu->cpu_timer); if (pcpu->target_freq != pcpu->policy->min) { -#ifdef CONFIG_SMP /* * Entering idle while not at lowest speed. On some * platforms this can hold the other CPU(s) at that speed @@ -285,8 +291,7 @@ static void cpufreq_interactive_idle_start(void) &pcpu->cpu_timer, jiffies + usecs_to_jiffies(timer_rate)); } -#endif - } else { + } else if (governidle) { /* * If at min speed and entering idle after load has * already been evaluated, and a timer has been set just in @@ -708,7 +713,10 @@ static int __init cpufreq_interactive_init(void) /* Initalize per-cpu timers */ for_each_possible_cpu(i) { pcpu = &per_cpu(cpuinfo, i); - init_timer(&pcpu->cpu_timer); + if (governidle) + init_timer(&pcpu->cpu_timer); + else + init_timer_deferrable(&pcpu->cpu_timer); pcpu->cpu_timer.function = cpufreq_interactive_timer; pcpu->cpu_timer.data = i; } -- 2.34.1