Re: [PATCH v5] cpuidle: Init cpuidle only for present CPUs

[Rafael J. Wysocki]

On Tue, Mar 11, 2025 at 3:43 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>
> On Fri, 7 Mar 2025 at 15:54, Jacky Bai <ping.bai@xxxxxxx> wrote:
> >
> > for_each_possible_cpu() is currently used to initialize cpuidle
> > in below cpuidle drivers:
> >   drivers/cpuidle/cpuidle-arm.c
> >   drivers/cpuidle/cpuidle-big_little.c
> >   drivers/cpuidle/cpuidle-psci.c
> >   drivers/cpuidle/cpuidle-qcom-spm.c
> >   drivers/cpuidle/cpuidle-riscv-sbi.c
> >
> > However, in cpu_dev_register_generic(), for_each_present_cpu()
> > is used to register CPU devices which means the CPU devices are
> > only registered for present CPUs and not all possible CPUs.
> >
> > With nosmp or maxcpus=0, only the boot CPU is present, lead
> > to the failure:
> >
> >   |  Failed to register cpuidle device for cpu1
> >
> > Then rollback to cancel all CPUs' cpuidle registration.
> >
> > Change for_each_possible_cpu() to for_each_present_cpu() in the
> > above cpuidle drivers to ensure it only registers cpuidle devices
> > for CPUs that are actually present.
> >
> > Fixes: b0c69e1214bc ("drivers: base: Use present CPUs in GENERIC_CPU_DEVICES")
> > Reviewed-by: Dhruva Gole <d-gole@xxxxxx>
> > Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> > Tested-by: Yuanjie Yang <quic_yuanjiey@xxxxxxxxxxx>
> > Signed-off-by: Jacky Bai <ping.bai@xxxxxxx>
>
> Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>
> Rafael, I assume you will pick these up? Or let me know if you want me
> to take them via my pmdomain tree.

I can pick it up.