null_blk: set use_per_node_hctx param to false
The defaults for the module is to instantiate itself with blk-mq and a
submit queue for each CPU node in the system.
To save resources, initialize instead with a single submit queue.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt
index 5603dad..b2830b4 100644
--- a/Documentation/block/null_blk.txt
+++ b/Documentation/block/null_blk.txt
@@ -65,7 +65,8 @@
III: Multi-queue specific parameters
-use_per_node_hctx=[0/1]: Default: 1
- If 1, the multi-queue block layer is instantiated with a hardware dispatch
- queue for each CPU node in the system. If 0, it is instantiated with the
- number of queues defined in the submit_queues parameter.
+use_per_node_hctx=[0/1]: Default: 0
+ 0: The number of submit queues are set to the value of the submit_queues
+ parameter.
+ 1: The multi-queue block layer is instantiated with a hardware dispatch
+ queue for each CPU node in the system.
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 8f2e7c3..9b0311b 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -101,9 +101,9 @@
module_param(hw_queue_depth, int, S_IRUGO);
MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64");
-static bool use_per_node_hctx = true;
+static bool use_per_node_hctx = false;
module_param(use_per_node_hctx, bool, S_IRUGO);
-MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: true");
+MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
static void put_tag(struct nullb_queue *nq, unsigned int tag)
{