On 04/28/2015 02:23 PM, Viresh Kumar wrote: > On 28 April 2015 at 13:48, Shilpasri G Bhat > <shilpa.b...@linux.vnet.ibm.com> wrote: >> My bad I haven't added explicit comment to state reason behind this change. >> >> I modified the definition of *throttle_check() to match the function >> definition >> to be called via smp_call() instead of adding an additional wrapper around >> *throttle_check(). >> >> OCC is a chip entity and any local throttle state changes should be >> associated >> to cpus belonging to that chip. The *throttle_check() will read the core >> register PMSR to verify throttling. All the cores in a chip will have the >> same >> throttled state as they are managed by a the same OCC in that chip. >> >> smp_call() is required to ensure *throttle_check() is called on a cpu >> belonging >> to the chip for which we have received throttled/unthrottled notification. We >> could be handling throttled/unthrottled notification of 'chip1' in 'chip2' >> so do >> an smp_call() on 'chip1'. > > Okay. Lets talk about the code that is already present in mainline. Isn't that > suffering from this issue ? If yes, then you need to bugfix that separately.
Nope. The upstream code does not have this issue as it does not have checks to detect unthrottling state. The unthrottling i.e, 'throttled=false' is being handled only in this patchset. Yes this can be fixed separately. > >> We are irq_disabled in powernv_cpufreq_occ_msg() the notification handler. >> Thus the use of kworker to do an smp_call and restore policy->cur. >> >> OCC_RESET is global event it affects frequency of all chips. Pmax capping is >> local event, it affects the frequency of a chip. >> > >>> That's a lot. I am not an expert here and so really can't comment on >>> the internals of ppc. But, is it patch solving a single problem ? I don't >>> know, I somehow got the impression that it can be split into multiple >>> (smaller & review-able) patches. Only if it makes sense. Your call. >> >> All the changes introduced in this patch is centered around opal_message >> notification handler powernv_cpufreq_occ_msg(). I can split it into multiple >> patches but it all will be relevant only to solve the above problem. > > And that's what I meant here. Yes, this all is solving a central problem, but > a patch must be divided into separate, independently working, entities. > Yup agree. Will do. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
