From f7c4cdc712ab803f7cdd3d47025081831f457ecc Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 19 Aug 2020 23:20:33 +0800 Subject: [PATCH] scsi: scsi_debug: Support host tagset When host_max_queue is set (> 0), set the Scsi_Host.host_tagset such that blk-mq will use a hostwide tagset over all SCSI host submission queues. This means that we may expose all submission queues and always use the hwq chosen by blk-mq. And since if sdebug_host_max_queue is set, sdebug_max_queue is fixed to the same value, we can simplify how sdebug_driver_template.can_queue is set. Signed-off-by: John Garry Tested-by: Douglas Gilbert Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe --- drivers/scsi/scsi_debug.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 1ad7260d4758..a87e40aec11f 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -4696,19 +4696,14 @@ fini: static struct sdebug_queue *get_queue(struct scsi_cmnd *cmnd) { u16 hwq; + u32 tag = blk_mq_unique_tag(cmnd->request); - if (sdebug_host_max_queue) { - /* Provide a simple method to choose the hwq */ - hwq = smp_processor_id() % submit_queues; - } else { - u32 tag = blk_mq_unique_tag(cmnd->request); + hwq = blk_mq_unique_tag_to_hwq(tag); - hwq = blk_mq_unique_tag_to_hwq(tag); + pr_debug("tag=%#x, hwq=%d\n", tag, hwq); + if (WARN_ON_ONCE(hwq >= submit_queues)) + hwq = 0; - pr_debug("tag=%#x, hwq=%d\n", tag, hwq); - if (WARN_ON_ONCE(hwq >= submit_queues)) - hwq = 0; - } return sdebug_q_arr + hwq; } @@ -7347,10 +7342,7 @@ static int sdebug_driver_probe(struct device *dev) sdbg_host = to_sdebug_host(dev); - if (sdebug_host_max_queue) - sdebug_driver_template.can_queue = sdebug_host_max_queue; - else - sdebug_driver_template.can_queue = sdebug_max_queue; + sdebug_driver_template.can_queue = sdebug_max_queue; if (!sdebug_clustering) sdebug_driver_template.dma_boundary = PAGE_SIZE - 1; @@ -7367,11 +7359,11 @@ static int sdebug_driver_probe(struct device *dev) } /* * Decide whether to tell scsi subsystem that we want mq. The - * following should give the same answer for each host. If the host - * has a limit of hostwide max commands, then do not set. + * following should give the same answer for each host. */ - if (!sdebug_host_max_queue) - hpnt->nr_hw_queues = submit_queues; + hpnt->nr_hw_queues = submit_queues; + if (sdebug_host_max_queue) + hpnt->host_tagset = 1; sdbg_host->shost = hpnt; *((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host; -- 2.25.1