On 05/20/2013 03:25 PM, Michael Wang wrote:
[]
>
> Yeah, that's right, I guess the issue is, although the policy->cpus is
> correct at a given time, after get cpu from it, it's possible to be
> changed, unless we disabled preempt or irq, or hotplug before we use it...
>
> Like such issue cases:
> get x from policy->cpus
> DOWN notifier
> change policy->cpus
> do offline x
> send ipi to x
>
> Will that happen?
May be we could do some test to confirm it?
diff --git a/drivers/cpufreq/cpufreq_governor.c
b/drivers/cpufreq/cpufreq_governor.c
index 443442d..449be88 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -26,6 +26,7 @@
#include <linux/tick.h>
#include <linux/types.h>
#include <linux/workqueue.h>
+#include <linux/cpu.h>
#include "cpufreq_governor.h"
@@ -180,8 +181,10 @@ void gov_queue_work(struct dbs_data *dbs_data,
struct cpufreq_policy *policy,
if (!all_cpus) {
__gov_queue_work(smp_processor_id(), dbs_data, delay);
} else {
+ get_online_cpus();
for_each_cpu(i, policy->cpus)
__gov_queue_work(i, dbs_data, delay);
+ put_online_cpus();
}
}
EXPORT_SYMBOL_GPL(gov_queue_work);
This is supposed to make WARN disappear, if it works, then BINGO :)
Regards,
Michael Wang
>
> Regards,
> Michael Wang
>
>
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