Messages in this thread Patch in this message | | | Date | Mon, 20 May 2013 16:56:45 +0800 | From | Michael Wang <> | Subject | Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule, round 2 |
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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 > > >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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