Previous commit can help remove all freeze for netlink newly created nbd device. But for the devices pre-created at module load(nbds_max default as 16), the nr_hw_queues was setting default as 1, then ioctl/netlink path will set the real connection count, and blk_mq_update_nr_hw_queues in nbd_start_device will introduce freeze. Add an nr_hw_queues module parameter so that users who know their expected connection count can pre-created devices with the right queue count to avoid this freeze too. Signed-off-by: Yang Erkun --- drivers/block/nbd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 2c7b09c70da2..f918c9efa9b2 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -166,6 +166,7 @@ static struct dentry *nbd_dbg_dir; static unsigned int nbds_max = 16; static int max_part = 16; +static int nr_hw_queues = 1; static int part_shift; static int nbd_dev_dbg_init(struct nbd_device *nbd); @@ -2752,8 +2753,10 @@ static int __init nbd_init(void) } nbd_dbg_init(); + if (nr_hw_queues < 1) + nr_hw_queues = 1; for (i = 0; i < nbds_max; i++) - nbd_dev_add(i, 1, 1); + nbd_dev_add(i, 1, nr_hw_queues); return 0; } @@ -2814,3 +2817,6 @@ module_param(nbds_max, int, 0444); MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); module_param(max_part, int, 0444); MODULE_PARM_DESC(max_part, "number of partitions per device (default: 16)"); +module_param(nr_hw_queues, int, 0444); +MODULE_PARM_DESC(nr_hw_queues, +"number of hardware queues for devices pre-created at module load (default: 1). "); -- 2.52.0