| Message ID | 20250306061805.2318154-1-ping.bai@nxp.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] cpuidle: psci: Init cpuidle only for present CPUs | expand |
On Thu, 6 Mar 2025 at 07:17, Jacky Bai <ping.bai@nxp.com> wrote: > > for_each_possible_cpu() is currently used to initialize cpuidle > in the PSCI cpuidle driver. > > 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, leading > to the failure: > > | Failed to register cpuidle device for cpu1 > > Change for_each_possible_cpu() to for_each_present_cpu() in the > PSCI cpuidle driver 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@ti.com> > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> > Tested-by: Yuanjie Yang <quic_yuanjiey@quicinc.com> > Signed-off-by: Jacky Bai <ping.bai@nxp.com> Is this problem specific to cpuidle-psci? Others are using for_each_possible_cpu() when registering their cpuidle drivers. Kind regards Uffe > --- > - v2 changes: > - Improve the changelog as suggested by Sudeep > --- > drivers/cpuidle/cpuidle-psci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > index 2562dc001fc1..00117e9b33e8 100644 > --- a/drivers/cpuidle/cpuidle-psci.c > +++ b/drivers/cpuidle/cpuidle-psci.c > @@ -410,7 +410,7 @@ static int psci_cpuidle_probe(struct platform_device *pdev) > struct cpuidle_driver *drv; > struct cpuidle_device *dev; > > - for_each_possible_cpu(cpu) { > + for_each_present_cpu(cpu) { > ret = psci_idle_init_cpu(&pdev->dev, cpu); > if (ret) > goto out_fail; > -- > 2.34.1 >
On Thu, Mar 06, 2025 at 11:53:14AM +0100, Ulf Hansson wrote: > On Thu, 6 Mar 2025 at 07:17, Jacky Bai <ping.bai@nxp.com> wrote: > > > > for_each_possible_cpu() is currently used to initialize cpuidle > > in the PSCI cpuidle driver. > > > > 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, leading > > to the failure: > > > > | Failed to register cpuidle device for cpu1 > > > > Change for_each_possible_cpu() to for_each_present_cpu() in the > > PSCI cpuidle driver 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@ti.com> > > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> > > Tested-by: Yuanjie Yang <quic_yuanjiey@quicinc.com> > > Signed-off-by: Jacky Bai <ping.bai@nxp.com> > > Is this problem specific to cpuidle-psci? > > Others are using for_each_possible_cpu() when registering their cpuidle drivers. > Good point. I assumed as this was very old patch, only this is left without conversion to using present_cpumask. Looks like there are many other drivers that need similar change. May be PSCI is most commonly used ones these days and hardly anyone tests with nosmp or maxcpus=1 on those platforms. But yes, all the users of for_each_possible_cpu() need to move to for_each_present_cpu() if they are relying on CPU device being registered.
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 2562dc001fc1..00117e9b33e8 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -410,7 +410,7 @@ static int psci_cpuidle_probe(struct platform_device *pdev) struct cpuidle_driver *drv; struct cpuidle_device *dev; - for_each_possible_cpu(cpu) { + for_each_present_cpu(cpu) { ret = psci_idle_init_cpu(&pdev->dev, cpu); if (ret) goto out_fail;
for_each_possible_cpu() is currently used to initialize cpuidle in the PSCI cpuidle driver. 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, leading to the failure: | Failed to register cpuidle device for cpu1 Change for_each_possible_cpu() to for_each_present_cpu() in the PSCI cpuidle driver 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@ti.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Yuanjie Yang <quic_yuanjiey@quicinc.com> Signed-off-by: Jacky Bai <ping.bai@nxp.com> --- - v2 changes: - Improve the changelog as suggested by Sudeep --- drivers/cpuidle/cpuidle-psci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)