The four ACPI architectures only create sysfs entries using register_cpu()
for present CPUs, whereas GENERIC_CPU_DEVICES does this for possible CPUs.
Only two of the eight architectures that use GENERIC_CPU_DEVICES have a
distinction between present and possible CPUs.
To allow all four ACPI architectures to use GENERIC_CPU_DEVICES, change
it to use for_each_present_cpu().
The following architectures use GENERIC_CPU_DEVICES but are not SMP,
so possible == present:
* m68k
* microblaze
* nios2
The following architectures use GENERIC_CPU_DEVICES and consider
possible == present:
* csky: setup_smp()
* hexagon: compare smp_start_cpus() and smp_prepare_cpus()
* parisc: smp_prepare_boot_cpu() marks the boot cpu as present,
processor_probe() sets possible for all CPUs and present for all CPUs
except the boot cpu.
um appears to be a subarchitecture of x86.
The remaining architecture using GENERIC_CPU_DEVICES is openrisc,
where smp_init_cpus() makes all CPUs < NR_CPUS possible, whereas
smp_prepare_cpus() only makes CPUs < setup_max_cpus present. After this
change, openrisc systems that boot with max_cpus=1 would not see other
CPUs present in sysfs. This should not be a problem as these CPUs can't
be brought online as _cpu_up() checks cpu_present().
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
drivers/base/cpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 4c98849577d4..cf6407c34ede 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -500,7 +500,7 @@ static void __init cpu_dev_register_generic(void)
#ifdef CONFIG_GENERIC_CPU_DEVICES
int i;
- for_each_possible_cpu(i) {
+ for_each_present_cpu(i) {
if (register_cpu(&per_cpu(cpu_devices, i), i))
panic("Failed to register CPU device");
}
--
2.30.2
|