Messages in this thread | | | Subject | Re: [PATCH V2 1/2] sched/core: Rename and move schedutil_cpu_util() to core.c | From | Lukasz Luba <> | Date | Fri, 23 Oct 2020 12:08:38 +0100 |
| |
On 10/23/20 11:54 AM, Viresh Kumar wrote: > On 23-10-20, 12:34, Peter Zijlstra wrote: >> On Fri, Oct 23, 2020 at 03:50:20PM +0530, Viresh Kumar wrote: >>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >>> index d2003a7d5ab5..369ff54d11d4 100644 >>> --- a/kernel/sched/core.c >>> +++ b/kernel/sched/core.c >>> @@ -5117,6 +5117,119 @@ struct task_struct *idle_task(int cpu) >>> return cpu_rq(cpu)->idle; >>> } >>> >>> +/* >>> + * This function computes an effective utilization for the given CPU, to be >>> + * used for frequency selection given the linear relation: f = u * f_max. >>> + * >>> + * The scheduler tracks the following metrics: >>> + * >>> + * cpu_util_{cfs,rt,dl,irq}() >>> + * cpu_bw_dl() >>> + * >>> + * Where the cfs,rt and dl util numbers are tracked with the same metric and >>> + * synchronized windows and are thus directly comparable. >>> + * >>> + * The cfs,rt,dl utilization are the running times measured with rq->clock_task >>> + * which excludes things like IRQ and steal-time. These latter are then accrued >>> + * in the irq utilization. >>> + * >>> + * The DL bandwidth number otoh is not a measured metric but a value computed >>> + * based on the task model parameters and gives the minimal utilization >>> + * required to meet deadlines. >>> + */ >>> +unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, >>> + unsigned long max, enum cpu_util_type type, >>> + struct task_struct *p) >>> +{ >> ... >>> +} >>> + >>> +unsigned long sched_cpu_util(int cpu, enum cpu_util_type type, >>> + unsigned long max) >>> +{ >>> + return effective_cpu_util(cpu, cpu_util_cfs(cpu_rq(cpu)), max, type, >>> + NULL); >>> +} >> >> Shouldn't all that be: #ifdef CONFIG_SMP ? > > I didn't realize that these matrices are only available in case of SMP > and that's why schedutil isn't available for !SMP. I wonder what we > should be doing in cpufreq_cooling now ? Make it depend on SMP ? Or > calculate load the traditional way (the stuff I just removed) for !SMP > case ?
IMO the !SMP can leave with the old design, so keeping two implementations under #ifdef CONFIG_SMP is fair I would say in this case.
There are popular platforms !SMP (BeagleBone, RPi1, RPiZero) but I haven't heard anyone was using IPA on them.
Regards, Lukasz
> > :) >
| |