Support a shared tag bitmap, whereby request tags are unique over all submission queues, and not just per submission queue. As such, per device total queue depth is normally hw_queue_depth * submit_queues, but hw_queue_depth when set. And a similar story for when shared_tags is set, where that is the queue depth over all null blk devices. Signed-off-by: John Garry <john.garry@xxxxxxxxxx> --- drivers/block/null_blk_main.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 47a9dad880af..19c04e074880 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -164,6 +164,10 @@ static bool shared_tags; module_param(shared_tags, bool, 0444); MODULE_PARM_DESC(shared_tags, "Share tag set between devices for blk-mq"); +static bool g_shared_tag_bitmap; +module_param_named(shared_tag_bitmap, g_shared_tag_bitmap, bool, 0444); +MODULE_PARM_DESC(shared_tag_bitmap, "Use shared tag bitmap for all submission queues for blk-mq"); + static int g_irqmode = NULL_IRQ_SOFTIRQ; static int null_set_irqmode(const char *str, const struct kernel_param *kp) @@ -1692,6 +1696,8 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set) set->flags = BLK_MQ_F_SHOULD_MERGE; if (g_no_sched) set->flags |= BLK_MQ_F_NO_SCHED; + if (g_shared_tag_bitmap) + set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; set->driver_data = NULL; if ((nullb && nullb->dev->blocking) || g_blocking) -- 2.26.2
