On Thu, Jul 03, 2025 at 08:43:01AM +0200, Hannes Reinecke wrote: > All of these drivers are not aware of CPU hotplug, and as such > will not be notified when the number of CPUs changes.
Ah, this explains this part. > But you use 'blk_mq_online_queue_affinity()' for all of these > drivers. All these drivers are also using blk_mq_num_online_queue. When I only used cpu_possible_mask the resulting mapping was not usable. > Wouldn't 'blk_mq_possible_queue_affinit()' a better choice here > to insulate against CPU hotplug effects? With this mask the queues will be distributed to all possible CPUs and some of the hardware queues could be assigned to offline CPUs. I think this would work but the question is, is this okay to leave some of the perfomance on the road? I am not against this, just saying it would change the existing behavior. > Also some drivers which are using irq affinity (eg aacraid, lpfc) are > missing from these conversions. Why? I was not aware of aacraid. I started to work on lpfc and well let's put it this way, it's complicated. lpfc needs a lot of work to make it isolcpus aware.
