On Wed, Jul 22, 2020 at 12:23:44AM +0000, benbjiang(蒋彪) wrote: > > > > +/* > > + * This function takes care of adjusting the min_vruntime of siblings of > > + * a core during coresched enable/disable. > > + * This is called in stop machine context so no need to take the rq lock. > Hi, > > IMHO, it seems that stop machine context cannot guarantee race free. The > param *cpu* maybe not *this_cpu*, rq lock should be taken even in stop > machine context, and irq should be disabled too, to avoid potential races > with other contexts. >
In stop machine context, all CPUs except the active ones are spinning with irq disabled and in this invocation of stop_machine(), only one CPU is active so I don't think race is possible.
