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authorThomas Renninger <trenn@suse.de>2007-07-09 11:35:28 -0700
committerDave Jones <davej@redhat.com>2007-07-13 01:29:51 -0400
commit084f34939424161669467c19280dbcf637730314 (patch)
tree85285adb98b7306a28152cf48bfae98d3f1f05c8 /drivers
parent91973de736bc97dc04156242c5a4b00993b6c902 (diff)
[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 <trenn@suse.de> Signed-off-by: Mattia Dongili <malattia@linux.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/cpufreq/cpufreq.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 99f9c3c2384..2f6a73c01b7 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);