[PATCH v2] null_blk: add "no_sched" module parameter

[PATCH v2] null_blk: add "no_sched" module parameter

[weiping zhang]

add an option that disable io scheduler for null block device.

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
---
 drivers/block/null_blk.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index bd92286..38f4a8c 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -154,6 +154,10 @@ enum {
 	NULL_Q_MQ		= 2,
 };
 
+static int g_no_sched;
+module_param_named(no_sched, g_no_sched, int, S_IRUGO);
+MODULE_PARM_DESC(no_sched, "No io scheduler");
+
 static int g_submit_queues = 1;
 module_param_named(submit_queues, g_submit_queues, int, S_IRUGO);
 MODULE_PARM_DESC(submit_queues, "Number of submission queues");
@@ -1754,6 +1758,8 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
 	set->numa_node = nullb ? nullb->dev->home_node : g_home_node;
 	set->cmd_size	= sizeof(struct nullb_cmd);
 	set->flags = BLK_MQ_F_SHOULD_MERGE;
+	if (g_no_sched)
+		set->flags |= BLK_MQ_F_NO_SCHED;
 	set->driver_data = NULL;
 
 	if ((nullb && nullb->dev->blocking) || g_blocking)
-- 
2.9.4

Re: [PATCH v2] null_blk: add "no_sched" module parameter

[Jens Axboe]

On 09/30/2017 03:49 AM, weiping zhang wrote:
> add an option that disable io scheduler for null block device.

Applied for 4.15, thanks.

-- 
Jens Axboe