Fixes race between udev and hotplugged CPU registration, described at https://lkml.org/lkml/2012/4/30/198 by defining "online" attribute statically so that device_add() would create it before notifying udev about new CPU.
Signed-off-by: Igor Mammedov <[email protected]> --- drivers/base/cpu.c | 34 +++++++++++++++++++++------------- 1 files changed, 21 insertions(+), 13 deletions(-) diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 02e4d73..6578030 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -64,18 +64,21 @@ static ssize_t __ref store_online(struct device *dev, } static DEVICE_ATTR(online, 0644, show_online, store_online); -static void __cpuinit register_cpu_control(struct cpu *cpu) -{ - device_create_file(&cpu->dev, &dev_attr_online); -} +static struct attribute *hotplug_cpu_attrs[] = { + &dev_attr_online.attr, + NULL +}; + +static struct attribute_group hotplug_cpu_attr_group = { + .attrs = hotplug_cpu_attrs, +}; + void unregister_cpu(struct cpu *cpu) { int logical_cpu = cpu->dev.id; unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); - device_remove_file(&cpu->dev, &dev_attr_online); - device_unregister(&cpu->dev); per_cpu(cpu_sys_devices, logical_cpu) = NULL; return; @@ -101,11 +104,6 @@ static ssize_t cpu_release_store(struct device *dev, static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store); #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ - -#else /* ... !CONFIG_HOTPLUG_CPU */ -static inline void register_cpu_control(struct cpu *cpu) -{ -} #endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_KEXEC @@ -150,6 +148,16 @@ static const struct attribute_group *common_cpu_attr_groups[] = { NULL }; +static const struct attribute_group *hotplugable_cpu_attr_groups[] = { +#ifdef CONFIG_KEXEC + &crash_note_cpu_attr_group, +#endif +#ifdef CONFIG_HOTPLUG_CPU + &hotplug_cpu_attr_group, +#endif + NULL +}; + /* * Print cpu online, possible, present, and system maps */ @@ -265,9 +273,9 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) cpu->dev.bus->uevent = arch_cpu_uevent; #endif cpu->dev.groups = common_cpu_attr_groups; + if (cpu->hotpluggable) + cpu->dev.groups = hotplugable_cpu_attr_groups; error = device_register(&cpu->dev); - if (!error && cpu->hotpluggable) - register_cpu_control(cpu); if (!error) per_cpu(cpu_sys_devices, num) = &cpu->dev; if (!error) -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
