On Wed, Jul 26, 2017 at 10:34:43AM -0700, Christoph Hellwig wrote: > On Tue, Jul 25, 2017 at 03:24:08PM -0700, Shaohua Li wrote: > > Disable CONIFG_SMP, kernel crashes at boot time, here is the log. > > I can reproduce the issue. Unfortunately the addresss in the bug > doesn't make any sense to me when resolving it using gdb, as t just > points to the line where blk_mq_init_queue calls > blk_alloc_queue_node. > > Can you check if you get better results in your build?
It's crashing on that line because ctrl->tagset is NULL, which is because... irq_create_affinity_masks() returns NULL on !CONFIG_SMP -> pci_irq_get_affinity() returns NULL -> blk_mq_pci_map_queues() returns -EINVAL -> blk_mq_alloc_tag_set() returns -EINVAL -> nvme_dev_add() doesn't set ctrl->tagset The two-fold fix would be to make the nvme driver handle blk_mq_alloc_tag_set() failing and to fall back to a dumb mapping in blk_mq_pci_map_queues(), but I don't know what the best way to do those is.
