On Sun, Apr 08, 2018 at 05:48:08PM +0800, Ming Lei wrote: > >From commit 4b855ad37194 ("blk-mq: Create hctx for each present CPU), > blk-mq doesn't remap queue after CPU topo is changed, that said when > some of these offline CPUs become online, they are still mapped to > hctx 0, then hctx 0 may become the bottleneck of IO dispatch and > completion. > > This patch sets up the mapping from the beginning, and aligns to > queue mapping for PCI device (blk_mq_pci_map_queues()). Please kill the now pointless cpu_to_queue_index function. Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@xxxxxx>