null_blk: add module parameters for 4 options

Add as module parameters these options:

memory_backed
discard
mbps
cache_size

Previously these could only be set via configfs.

Still missing is bad_blocks.

The kernel test robot found a documentation formatting issue in v1 of
this patch.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>
Link: https://lore.kernel.org/r/20220708174943.87787-2-vincent.fu@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Vincent Fu 2022-07-08 17:49:49 +00:00 committed by Jens Axboe
parent ce11bdf946
commit 058efe000b
2 changed files with 42 additions and 0 deletions

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@ -72,6 +72,28 @@ submit_queues=[1..nr_cpus]: Default: 1
hw_queue_depth=[0..qdepth]: Default: 64 hw_queue_depth=[0..qdepth]: Default: 64
The hardware queue depth of the device. The hardware queue depth of the device.
memory_backed=[0/1]: Default: 0
Whether or not to use a memory buffer to respond to IO requests
= =============================================
0 Transfer no data in response to IO requests
1 Use a memory buffer to respond to IO requests
= =============================================
discard=[0/1]: Default: 0
Support discard operations (requires memory-backed null_blk device).
= =====================================
0 Do not support discard operations
1 Enable support for discard operations
= =====================================
cache_size=[Size in MB]: Default: 0
Cache size in MB for memory-backed device.
mbps=[Maximum bandwidth in MB/s]: Default: 0 (no limit)
Bandwidth limit for device performance.
Multi-queue specific parameters Multi-queue specific parameters
------------------------------- -------------------------------

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@ -201,6 +201,22 @@ static bool g_use_per_node_hctx;
module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444); module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, 0444);
MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
static bool g_memory_backed;
module_param_named(memory_backed, g_memory_backed, bool, 0444);
MODULE_PARM_DESC(memory_backed, "Create a memory-backed block device. Default: false");
static bool g_discard;
module_param_named(discard, g_discard, bool, 0444);
MODULE_PARM_DESC(discard, "Support discard operations (requires memory-backed null_blk device). Default: false");
static unsigned long g_cache_size;
module_param_named(cache_size, g_cache_size, ulong, 0444);
MODULE_PARM_DESC(mbps, "Cache size in MiB for memory-backed device. Default: 0 (none)");
static unsigned int g_mbps;
module_param_named(mbps, g_mbps, uint, 0444);
MODULE_PARM_DESC(mbps, "Limit maximum bandwidth (in MiB/s). Default: 0 (no limit)");
static bool g_zoned; static bool g_zoned;
module_param_named(zoned, g_zoned, bool, S_IRUGO); module_param_named(zoned, g_zoned, bool, S_IRUGO);
MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false"); MODULE_PARM_DESC(zoned, "Make device as a host-managed zoned block device. Default: false");
@ -650,6 +666,10 @@ static struct nullb_device *null_alloc_dev(void)
dev->irqmode = g_irqmode; dev->irqmode = g_irqmode;
dev->hw_queue_depth = g_hw_queue_depth; dev->hw_queue_depth = g_hw_queue_depth;
dev->blocking = g_blocking; dev->blocking = g_blocking;
dev->memory_backed = g_memory_backed;
dev->discard = g_discard;
dev->cache_size = g_cache_size;
dev->mbps = g_mbps;
dev->use_per_node_hctx = g_use_per_node_hctx; dev->use_per_node_hctx = g_use_per_node_hctx;
dev->zoned = g_zoned; dev->zoned = g_zoned;
dev->zone_size = g_zone_size; dev->zone_size = g_zone_size;