On 25/04/23 22:32, Yury Norov wrote: > On Tue, Apr 25, 2023 at 10:54:48AM +0100, Valentin Schneider wrote: >> On 19/04/23 22:19, Yury Norov wrote: >> > +/** >> > + * for_each_numa_cpu - iterate over cpus in increasing order taking into account >> > + * NUMA distances from a given node. >> > + * @cpu: the (optionally unsigned) integer iterator >> > + * @hop: the iterator variable, must be initialized to a desired minimal hop. >> > + * @node: the NUMA node to start the search from. >> > + * @mask: the cpumask pointer >> > + * >> > + * Requires rcu_lock to be held. >> > + */ >> > +#define for_each_numa_cpu(cpu, hop, node, mask) \ >> > + for ((cpu) = 0, (hop) = 0; \ >> > + (cpu) = sched_numa_find_next_cpu((mask), (cpu), (node), &(hop)),\ >> > + (cpu) < nr_cpu_ids; \ >> > + (cpu)++) >> > + >> >> I think we can keep sched_numa_find_next_cpu() as-is, but could we make >> that macro use cpu_possible_mask by default? We can always add a variant >> if/when we need to feed in a different mask. > > As mentioned in discussion to the driver's patch, all that numa things > imply only online CPUs, so cpu_possible_mask may mislead to some extent. > > Anyways, can you elaborate what you exactly want? Like this? > > #define for_each_numa_online_cpu(cpu, hop, node) \ > for_each_numa_cpu(cpu, hop, node, cpu_online_mask) Yeah, something like that. Like you said, the NUMA cpumasks built by the scheduler reflect the online topology, so s/possible/online/ shouldn't change much here.
