Messages in this thread | | | Date | Thu, 20 Mar 2014 15:15:59 +0530 | From | "Srivatsa S. Bhat" <> | Subject | Re: [RFC v3] cpufreq: Make sure frequency transitions are serialized |
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On 03/20/2014 03:03 PM, Viresh Kumar wrote: > On 20 March 2014 14:54, Srivatsa S. Bhat > <srivatsa.bhat@linux.vnet.ibm.com> wrote: >> On 03/20/2014 02:07 PM, Viresh Kumar wrote: >>> WARN_ON(policy->transition_ongoing); >>> >> >> I guess you meant WARN_ON(!policy->transition_ongoing) >> perhaps? > > Ooops!! > >> I'm not sure whether its really worth it, because it kinda looks >> obvious. Not sure what kind of bugs it would catch. I can't think of any >> such scenario :-( > > Just to catch if somebody is sending a POSTCHANGE one without first > sending a PRECHANGE one.. Just another check to make sure things are > in order. >
Well, that's unlikely, since they will have to call _end() before _begin() :-) That's the power of having great function names - they make it impossible to use them incorrectly ;-) But anyway, I can add the check, just in case somebody misses even such an obvious cue! :-)
By the way, I'm also thinking of using a spinlock instead of a mutex. The critical section is tiny and we don't sleep inside the critical section - sounds like the perfect case for a spinlock.
Regards, Srivatsa S. Bhat
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