Re: CPUFREQ-CPUHOTPLUG: Possible circular locking dependency

Andrew Morton
2006-11-29T21:06:19Z

On Wed, 29 Nov 2006 20:54:04 +0530
Gautham R Shenoy <ego@in.ibm.com> wrote:

> Ok, so to cut the long story short,
> - While changing governor from anything to
> ondemand, locks are taken in the following order
>
> policy->lock ===> dbs_mutex ===> workqueue_mutex.
>
> - While offlining a cpu, locks are taken in the following order
>
> cpu_add_remove_lock ==> sched_hotcpu_mutex ==> workqueue_mutex ==
> ==> cache_chain_mutex ==> policy->lock.

What functions are taking all these locks? (ie: the callpath?)