[PATCH V3 4/4] loop: allow user to set the queue depth
From: Chaitanya Kulkarni <kch@nvidia.com>
Date: 2022-02-15 21:34:09
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
Instead of hardcoding queue depth allow user to set the hw queue depth using module parameter. Set default value to 128 to retain the existing behavior. Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Himanshu Madhani <redacted> --- Detailed test log for this module param is at the end of the cover-letter. --- drivers/block/loop.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 18b30a56bfc4..c9a732a22767 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c@@ -85,6 +85,7 @@ #include <linux/uaccess.h> #define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ) +#define LOOP_DEFAULT_HW_Q_DEPTH (128) static DEFINE_IDR(loop_index_idr); static DEFINE_MUTEX(loop_ctl_mutex);
@@ -1785,6 +1786,24 @@ module_param(max_loop, int, 0444); MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); module_param(max_part, int, 0444); MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); + +static int hw_queue_depth = LOOP_DEFAULT_HW_Q_DEPTH; + +static int loop_set_hw_queue_depth(const char *s, const struct kernel_param *p) +{ + int ret = kstrtoint(s, 10, &hw_queue_depth); + + return (ret || (hw_queue_depth < 1)) ? -EINVAL : 0; +} + +static const struct kernel_param_ops loop_hw_qdepth_param_ops = { + .set = loop_set_hw_queue_depth, + .get = param_get_int, +}; + +device_param_cb(hw_queue_depth, &loop_hw_qdepth_param_ops, &hw_queue_depth, 0444); +MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 128"); + MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR);
@@ -1979,7 +1998,7 @@ static int loop_add(int i) lo->tag_set.ops = &loop_mq_ops; lo->tag_set.nr_hw_queues = 1; - lo->tag_set.queue_depth = 128; + lo->tag_set.queue_depth = hw_queue_depth; lo->tag_set.numa_node = NUMA_NO_NODE; lo->tag_set.cmd_size = sizeof(struct loop_cmd); lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING |
--
2.29.0