On Wed, Jul 26, 2023 at 05:40:18PM +0800, Ming Lei wrote: > Hi, > > On arm and ppc64, 'maxcpus=1' is required for kdump kernel, > see `Documentation/admin-guide/kdump/kdump.rst`, so num_possible_cpus() > still returns all CPUs because 'maxcpus=1' just bring up one single > cpu core during booting. Just as said last time: Please drop the odd is_kdump_kernel checks in blk_mq_update_queue_map and blk_mq_alloc_tag_set instead of sprinkling this crap even further.