null_blk: Support shared tag bitmap (0905053b) · Commits · 戴 / test

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@huawei.com> Tested-by:

Douglas Gilbert <dgilbert@interlog.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

drivers/block/null_blk_main.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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)

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