On 01/04/2019 11:21, Julien Grall wrote: > Hi, > > On 3/29/19 3:08 PM, Juergen Gross wrote: >> cpu_disable_scheduler() is being called from __cpu_disable() today. >> There is no need to execute it on the cpu just being disabled, so use >> the CPU_DEAD case of the cpu notifier chain. Moving the call out of >> stop_machine() context is fine, as we just need to hold the domain RCU >> lock and need the scheduler percpu data to be still allocated. >> >> Add another hook for CPU_DOWN_PREPARE to bail out early in case >> cpu_disable_scheduler() would fail. This will avoid crashes in rare >> cases for cpu hotplug or suspend. >> >> While at it remove a superfluous smp_mb() in the ARM __cpu_disable() >> incarnation. > > This is not obvious why the smp_mb() is superfluous. Can you please > provide more details on why this is not necessary?
cpumask_clear_cpu() should already have the needed semantics, no? It is based on clear_bit() which is defined to be atomic. Juergen _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
