diff options
Diffstat (limited to 'Documentation/block/null_blk.txt')
| -rw-r--r-- | Documentation/block/null_blk.txt | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt index 3140dbd860d8c..733927a7b501a 100644 --- a/Documentation/block/null_blk.txt +++ b/Documentation/block/null_blk.txt @@ -38,7 +38,7 @@ gb=[Size in GB]: Default: 250GB bs=[Block size (in bytes)]: Default: 512 bytes The block size reported to the system. -nr_devices=[Number of devices]: Default: 2 +nr_devices=[Number of devices]: Default: 1 Number of block devices instantiated. They are instantiated as /dev/nullb0, etc. @@ -52,13 +52,13 @@ irqmode=[0-2]: Default: 1-Soft-irq 2: Timer: Waits a specific period (completion_nsec) for each IO before completion. -completion_nsec=[ns]: Default: 10.000ns +completion_nsec=[ns]: Default: 10,000ns Combined with irqmode=2 (timer). The time each completion event must wait. -submit_queues=[0..nr_cpus]: +submit_queues=[1..nr_cpus]: The number of submission queues attached to the device driver. If unset, it - defaults to 1 on single-queue and bio-based instances. For multi-queue, - it is ignored when use_per_node_hctx module parameter is 1. + defaults to 1. For multi-queue, it is ignored when use_per_node_hctx module + parameter is 1. hw_queue_depth=[0..qdepth]: Default: 64 The hardware queue depth of the device. @@ -73,3 +73,12 @@ use_per_node_hctx=[0/1]: Default: 0 use_lightnvm=[0/1]: Default: 0 Register device with LightNVM. Requires blk-mq and CONFIG_NVM to be enabled. + +no_sched=[0/1]: Default: 0 + 0: nullb* use default blk-mq io scheduler. + 1: nullb* doesn't use io scheduler. + +shared_tags=[0/1]: Default: 0 + 0: Tag set is not shared. + 1: Tag set shared between devices for blk-mq. Only makes sense with + nr_devices > 1, otherwise there's no tag set to share. |