On Wed, Dec 07, 2016 at 05:03:48PM -0500, Dan Streetman wrote: > Change each queue's cq_vector to match its qid, instead of qid - 1. > > The first queue is always the admin queue, and the remaining queues are > I/O queues. The interrupt vectors they use are all in the same array, > however, the vector indexes for the admin and I/O queues are setup > differently; the admin queue's cq_vector is manually set to 0, while > each I/O queue's cq_vector is set to qid - 1. Since the admin queue > is qid 0, and the I/O queues start at qid 1, using qid - 1 is wrong for the > I/O queues, as it makes the first I/O queue (qid 1) share the vector from > the admin queue (qid 0), and no queue uses the last interrupt vector. > Instead, each I/O queue should set their cq_vector to qid.
pci_alloc_irq_vectors doesn't know you intend to make the first vector special, so it's going to come up with a CPU affinity from blk_mq_pci_map_queues that clashes with what you've programmed in the IO completion queues.
