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-rw-r--r--Documentation/block/null_blk.txt20
1 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt
index 9e1b047fd13d..5603dad5534b 100644
--- a/Documentation/block/null_blk.txt
+++ b/Documentation/block/null_blk.txt
@@ -18,7 +18,7 @@ The following instances are possible:
- Bio-based. IO requests are submitted directly to the device driver.
- Directly accepts bio data structure and returns them.
-All of them has a completion queue for each core in the system.
+All of them have a completion queue for each core in the system.
II. Module parameters applicable for all instances:
@@ -30,7 +30,7 @@ queue_mode=[0-2]: Default: 2-Multi-queue
2: Multi-queue.
home_node=[0--nr_nodes]: Default: NUMA_NO_NODE
- Selects what socket the data structures is allocated from.
+ Selects what CPU node the data structures are allocated from.
gb=[Size in GB]: Default: 250GB
The size of the device reported to the system.
@@ -38,34 +38,34 @@ gb=[Size in GB]: Default: 250GB
bs=[Block size (in bytes)]: Default: 512 bytes
The block size reported to the system.
-nr_devices=[Num. devices]: Default: 2
+nr_devices=[Number of devices]: Default: 2
Number of block devices instantiated. They are instantiated as /dev/nullb0,
etc.
-irq_mode=[0-2]: Default: Soft-irq
+irq_mode=[0-2]: Default: 1-Soft-irq
The completion mode used for completing IOs to the block-layer.
0: None.
- 1: Soft-irq. Uses ipi to complete IOs across sockets. Simulates the overhead
- when IOs are issued from another socket than the home the device is
+ 1: Soft-irq. Uses IPI to complete IOs across CPU nodes. Simulates the overhead
+ when IOs are issued from another CPU node than the home the device is
connected to.
2: Timer: Waits a specific period (completion_nsec) for each IO before
completion.
-completion_nsec=[Num. ns]: Default: 10.000ns
+completion_nsec=[ns]: Default: 10.000ns
Combined with irq_mode=2 (timer). The time each completion event must wait.
submit_queues=[0..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,
- its ignored when use_per_node_hctx module parameter is 1.
+ it is ignored when use_per_node_hctx module parameter is 1.
-hw_queue_depth=[0..qdepth]: Defaults: 64
+hw_queue_depth=[0..qdepth]: Default: 64
The hardware queue depth of the device.
III: Multi-queue specific parameters
-use_per_node_hctx=[0/1]: Defaults: 1
+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.