Messages in this thread | | | Date | Tue, 25 May 2021 12:49:15 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v5 1/3] sched/fair: Introduce the burstable CFS controller |
| |
On Mon, May 24, 2021 at 08:42:03PM +0800, changhuaixin wrote:
> >> --- a/kernel/sysctl.c > >> +++ b/kernel/sysctl.c > >> @@ -1816,6 +1816,15 @@ static struct ctl_table kern_table[] = { > >> .proc_handler = proc_dointvec_minmax, > >> .extra1 = SYSCTL_ONE, > >> }, > >> + { > >> + .procname = "sched_cfs_bw_burst_enabled", > >> + .data = &sysctl_sched_cfs_bw_burst_enabled, > >> + .maxlen = sizeof(unsigned int), > >> + .mode = 0644, > >> + .proc_handler = proc_dointvec_minmax, > >> + .extra1 = SYSCTL_ZERO, > >> + .extra2 = SYSCTL_ONE, > >> + }, > >> #endif > >> #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) > >> { > > > > What's the purpose of this new sysctl? By default it is disabled because > > burst==0, only if you set burst to some !0 value does this actually do > > anything. > > Originally, this is designed to turn burst feature off when the system becomes unstable. > Guess we can remove this as you have questioned it.
Is stability a concern? This is CFS after all, if we overload, we simply share time as per usual.
If there is a real use-case for a global knob to limit/disable this I don't object too much, but then please explicitly mention it.
| |