The patch titled
Restore previously used governor on a hot-replugged CPU
has been added to the -mm tree. Its filename is
restore-previously-used-governor-on-a-hot-replugged-cpu.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Restore previously used governor on a hot-replugged CPU
From: Thomas Renninger <trenn@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Mattia Dongili <malattia@xxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 23 ++++++++++++++++++++++-
1 files changed, 22 insertions(+), 1 deletion(-)
diff -puN drivers/cpufreq/cpufreq.c~restore-previously-used-governor-on-a-hot-replugged-cpu drivers/cpufreq/cpufreq.c
--- a/drivers/cpufreq/cpufreq.c~restore-previously-used-governor-on-a-hot-replugged-cpu
+++ a/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_d
}
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_d
/* 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
}
#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
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);
_
Patches currently in -mm which might be from trenn@xxxxxxx are
git-acpi.patch
exit-acpi-processor-module-gracefully-if-acpi-is-disabled.patch
git-cpufreq.patch
restore-previously-used-governor-on-a-hot-replugged-cpu.patch
-
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