On Sep 28, 2006, at 2:00 PM, Iain Hibbert wrote:

> On Thu, 28 Sep 2006, Juan RP wrote:
>
>> Any more suggestions about the code?
>
> 	simple_lock(&sysmon_cpufreq_slock);
> 	error = prop_dictionary_copyout_ioctl(plist, cmd, DEV_PROP_D);
> 	simple_unlock(&sysmon_cpufreq_slock);
>
> I am not sure that this is altogether safe - if the copyout sleeps  
> because
> ENOMEM, and another thread tries to get the lock in the meantime  
> does that
> not just lock the CPU?  (is a spinlock required?)

This code is actually wrong --- you're not allowed to hold a  
simple_lock across a sleep.

> If another thread changes the dictionary during the externalize, I  
> *think*
> it will just break the iterators and you will get an error. Jason?

Correct.

-- thorpej