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. > 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. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev