On 06/25/2013 05:09 PM, Heiko Carstens wrote: > On Tue, Jun 25, 2013 at 03:24:09PM +0800, Chen Gang wrote: >> On 06/25/2013 02:48 PM, Heiko Carstens wrote: >>> On Tue, Jun 25, 2013 at 09:46:45AM +0800, Chen Gang wrote: >>>>> When smp_add_present_cpu() fails, it has reset all things excluding >>>>> 'c->hotpluggable', so need reset it as original state completely. >>>>> >>>>> + c->hotpluggable = 0; >>>>> return rc; >>> No, that doesn't make sense. All cpus on s390 are always hotplugable. >>> It really doesn't matter if the value of this field is 0 or 1 after >>> an error. >>> >> >> If so, is it better to set 'c->hotpluggable' for all cpus on s390 during >> initializing ? > > No, just leave the code as it is. > Currently we have 3 possible states for 'struct cpu': initialized, and set hotplugable. unitialized, and set hotplugable. unitialized, and unset hotplugable. Either 2nd or 3rd is inconsistent. The cpu_is_hotplugable() will be used in kernel/rcutorture.c. I do not know whether it will cause issue or not, but it seems dangerous when __smp_rescan_cpus() has already called, and has some unsucessfull call of smp_add_present_cpu(). Please help check. Thanks. -- Chen Gang Asianux Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
