On Mon, May 29, 2017 at 11:20:24AM +0200, Dietmar Eggemann wrote: > Hi Greg, > > On 05/26/2017 08:36 PM, Greg KH wrote: > > On Fri, May 26, 2017 at 11:10:32AM +0100, Juri Lelli wrote: > > > Hi, > > > > > > On 25/05/17 15:18, Greg KH wrote: > > > > On Thu, Apr 20, 2017 at 03:43:16PM +0100, Juri Lelli wrote: > > [...] > > > > > But this is all really topology stuff, right? Why use "capacity" at > > > > all: > > > > topology_normalize_cpu() > > > > topology_parse_cpu() > > > > topology_scale_cpu() > > > > topology_set_scale() > > > > ? > > > > > > > > It's always best to put the "subsystem" name first, we have a bad > > > > history of getting this wrong in the past by putting the verb first, not > > > > the noun. > > > > > > > > > > topology_ works for me. However, I'd keep "capacity" in the names, as we > > > might need to topology_normalize_cpu_somethingelse() (etc.) in the > > > future? > > > > Worry about the future, in the future. Change the names then, _IF_ it > > becomes an issue. Try to be short and simple please. > > > > > Updated patch follows. I kept Catalin and Russell's acks as I only > > > renamed the functions, please shout if that's not OK. > > > > > > Greg, if you are fine with this approach, do you still want a complete > > > v5 of the set or can you pick this up? > > > > Am I the one who is supposed to take all of these arm-specific patches? > > If so, that's fine, but I need to have acks from the arm maintainers... > > > > Oh, and drop "capacity" please :) > > Once we have driver/base/arch_topology.c in, we want to enable (cpu > micro-architectural + max frequency (OPPmax)) invariant and frequency > (OPPmin..OPPmax) invariant load-tracking/accounting in the task scheduler > for arm and arm64. > > The way to do this is to define the task scheduler interfaces > arch_scale_cpu_capacity() and arch_scale_freq_capacity() in arch specific > code: > > #define arch_scale_cpu_capacity topology_scale_cpu_capacity > #define arch_scale_freq_capacity topology_scale_freq_capacity > > In case an arch is not defining them, the default definitions in > kernel/sched/sched.h are used. > > So topology_scale_cpu() wouldn't be correct since we scale the _capacity_ by > the micro-architectural differences (hence cpu) and not the cpu. > > Likewise we will have a function topology_scale_freq_capacity indicating > that we scale the capacity by the frequency. > > Or would you prefer something like topology_scale_capacity_by_cpu() and > topology_scale_capacity_by_freq()? I think that if you are creating an api that the scheduler will use, you need to ask the scheduler maintainers/developers what they want to see here, as that would be up to them, not me... thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
