Messages in this thread | | | Date | Tue, 30 May 2006 10:10:06 -0400 | From | Dave Jones <> | Subject | Re: [patch 00/61] ANNOUNCE: lock validator -V1 |
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On Tue, May 30, 2006 at 07:45:47AM +0200, Arjan van de Ven wrote:
> One > --- > store_scaling_governor takes policy->lock and then calls __cpufreq_set_policy > __cpufreq_set_policy calls __cpufreq_governor > __cpufreq_governor calls __cpufreq_driver_target via cpufreq_governor_performance > __cpufreq_driver_target calls lock_cpu_hotplug() (which takes the hotplug lock) > > > Two > --- > cpufreq_stats_init lock_cpu_hotplug() and then calls cpufreq_stat_cpu_callback > cpufreq_stat_cpu_callback calls cpufreq_update_policy > cpufreq_update_policy takes the policy->lock > > > so this looks like a real honest AB-BA deadlock to me...
This looks a little clearer this morning. I missed the fact that sys_init_module isn't completely serialised, only the loading part. ->init routines can and will be called in parallel.
I don't see where cpufreq_update_policy takes policy->lock though. In my tree it just takes the per-cpu data->lock.
Time for more wake-up juice? or am I missing something obvious again?
Dave
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