From 084f34939424161669467c19280dbcf637730314 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Mon, 9 Jul 2007 11:35:28 -0700 Subject: [CPUFREQ] Restore previously used governor on a hot-replugged CPU Negative side effect: needs NR_CPUs pointer array of memory in CONFIG_HOTPLUG_CPU case. Still needs userspace track keeping and rewriting of governors if governors change while a CPU is not active (always the governor at CPU remove time is restored). Move of policy->user_policy.governor assignment is just a minor cleanup. http://bugzilla.kernel.org/show_bug.cgi?id=8671 Signed-off-by: Thomas Renninger Signed-off-by: Mattia Dongili Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 99f9c3c23845..2f6a73c01b71 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -39,6 +39,10 @@ */ static struct cpufreq_driver *cpufreq_driver; static struct cpufreq_policy *cpufreq_cpu_data[NR_CPUS]; +#ifdef CONFIG_HOTPLUG_CPU +/* This one keeps track of the previously set governor of a removed CPU */ +static struct cpufreq_governor *cpufreq_cpu_governor[NR_CPUS]; +#endif static DEFINE_SPINLOCK(cpufreq_driver_lock); /* @@ -770,9 +774,17 @@ static int cpufreq_add_dev (struct sys_device * sys_dev) } policy->user_policy.min = policy->cpuinfo.min_freq; policy->user_policy.max = policy->cpuinfo.max_freq; - policy->user_policy.governor = policy->governor; #ifdef CONFIG_SMP + +#ifdef CONFIG_HOTPLUG_CPU + if (cpufreq_cpu_governor[cpu]){ + policy->governor = cpufreq_cpu_governor[cpu]; + dprintk("Restoring governor %s for cpu %d\n", + policy->governor->name, cpu); + } +#endif + for_each_cpu_mask(j, policy->cpus) { if (cpu == j) continue; @@ -873,6 +885,7 @@ static int cpufreq_add_dev (struct sys_device * sys_dev) /* set default policy */ ret = __cpufreq_set_policy(policy, &new_policy); policy->user_policy.policy = policy->policy; + policy->user_policy.governor = policy->governor; unlock_policy_rwsem_write(cpu); @@ -969,6 +982,11 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev) } #ifdef CONFIG_SMP + +#ifdef CONFIG_HOTPLUG_CPU + cpufreq_cpu_governor[cpu] = data->governor; +#endif + /* if we have other CPUs still registered, we need to unlink them, * or else wait_for_completion below will lock up. Clean the * cpufreq_cpu_data[] while holding the lock, and remove the sysfs @@ -989,6 +1007,9 @@ static int __cpufreq_remove_dev (struct sys_device * sys_dev) if (j == cpu) continue; dprintk("removing link for cpu %u\n", j); +#ifdef CONFIG_HOTPLUG_CPU + cpufreq_cpu_governor[j] = data->governor; +#endif cpu_sys_dev = get_cpu_sysdev(j); sysfs_remove_link(&cpu_sys_dev->kobj, "cpufreq"); cpufreq_cpu_put(data); -- cgit v1.2.3