Messages in this thread | | | Date | Tue, 14 May 2013 09:17:04 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [PATCH 2/2] cpu: make sure that cpu/online file created before KOBJ_ADD is emitted |
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On Tue, May 14, 2013 at 12:05:32AM +0200, Igor Mammedov wrote: > Fixes race between udev and hotplugged CPU registration, described at > https://lkml.org/lkml/2012/4/30/198
It would be better if you copy-n-pasted the contents of that URL in here. > by defining "online" attribute statically so that device_add() would > create it before notifying udev about new CPU.
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > --- > 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 >
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