On 26 June 2013 17:58, Guru Prasad <gurupras@xxxxxxxxxxx> wrote: > Hi, > > I'm working with a hardware simulator - Gem5 (http://gem5.org). I have > added some functionality to this simulator to modify memory frequency. > > I would like to add kernel support to manage memory frequency similar > to how cpu frequency is currently maintained so that I can study the > cost-benefit of memory frequency scaling. Have you looked at devfreq framework ? It should match with what you are looking for. devfreq is used to manage the frequency scaling of devices other than cpu like the gpu or the memory Vincent > > I copied all the generic cpufreq sources to a separate folder > kernel_source/drivers/memfreq and setup the drivers/Makefile. I have > also done the preliminary Kconfig modifications. > > A few things I don't follow are > > Where does the kernel actually implement the delay resulting from > cpuinfo.transition_latency? > Does the kernel stall for the duration of the delay? > > the per_cpu macro - I don't understand what this does..How can > I implement the same for memory - which I'm considering as a shared > resource rather than per_cpu. > > the subsys interface - What does it do and how do I reproduce > this for memory? Can I use the existing bus_type memory_subsys? > (drivers/base/memory.c) > > callback - This seems to be specific for > CONFIG_HOTPLUG_CPU..do I need to implement this at all for memfreq? > > sysfs interface - Is there any place I can look to > implement a nice sysfs interface similar to cpufreq? > > > Please let me know if there is anything I've missed out that might > complicate the process. > > > Regards > Guru > -- > To unsubscribe from this list: send the line "unsubscribe cpufreq" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
