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authorMatias Bjørling <m@bjorling.me>2013-12-20 18:10:59 -0500
committerJens Axboe <axboe@kernel.dk>2013-12-21 11:30:33 -0500
commit89ed05eea093d4c18df5d504d104f29b874fea29 (patch)
treeef54b84a4ed87f735d3460dc59303e2adfce8f12 /Documentation/block
parentd15ee6b1a43afbe1a6cece3bd8d336a9d5cb7060 (diff)
null_blk: corrections to documentation
Randy Dunlap reported a couple of grammar errors and unfortunate usages of socket/node/core. Signed-off-by: Matias Bjorling <m@bjorling.me> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'Documentation/block')
-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:
18 - Bio-based. IO requests are submitted directly to the device driver. 18 - Bio-based. IO requests are submitted directly to the device driver.
19 - Directly accepts bio data structure and returns them. 19 - Directly accepts bio data structure and returns them.
20 20
21All of them has a completion queue for each core in the system. 21All of them have a completion queue for each core in the system.
22 22
23II. Module parameters applicable for all instances: 23II. Module parameters applicable for all instances:
24 24
@@ -30,7 +30,7 @@ queue_mode=[0-2]: Default: 2-Multi-queue
30 2: Multi-queue. 30 2: Multi-queue.
31 31
32home_node=[0--nr_nodes]: Default: NUMA_NO_NODE 32home_node=[0--nr_nodes]: Default: NUMA_NO_NODE
33 Selects what socket the data structures is allocated from. 33 Selects what CPU node the data structures are allocated from.
34 34
35gb=[Size in GB]: Default: 250GB 35gb=[Size in GB]: Default: 250GB
36 The size of the device reported to the system. 36 The size of the device reported to the system.
@@ -38,34 +38,34 @@ gb=[Size in GB]: Default: 250GB
38bs=[Block size (in bytes)]: Default: 512 bytes 38bs=[Block size (in bytes)]: Default: 512 bytes
39 The block size reported to the system. 39 The block size reported to the system.
40 40
41nr_devices=[Num. devices]: Default: 2 41nr_devices=[Number of devices]: Default: 2
42 Number of block devices instantiated. They are instantiated as /dev/nullb0, 42 Number of block devices instantiated. They are instantiated as /dev/nullb0,
43 etc. 43 etc.
44 44
45irq_mode=[0-2]: Default: Soft-irq 45irq_mode=[0-2]: Default: 1-Soft-irq
46 The completion mode used for completing IOs to the block-layer. 46 The completion mode used for completing IOs to the block-layer.
47 47
48 0: None. 48 0: None.
49 1: Soft-irq. Uses ipi to complete IOs across sockets. Simulates the overhead 49 1: Soft-irq. Uses IPI to complete IOs across CPU nodes. Simulates the overhead
50 when IOs are issued from another socket than the home the device is 50 when IOs are issued from another CPU node than the home the device is
51 connected to. 51 connected to.
52 2: Timer: Waits a specific period (completion_nsec) for each IO before 52 2: Timer: Waits a specific period (completion_nsec) for each IO before
53 completion. 53 completion.
54 54
55completion_nsec=[Num. ns]: Default: 10.000ns 55completion_nsec=[ns]: Default: 10.000ns
56 Combined with irq_mode=2 (timer). The time each completion event must wait. 56 Combined with irq_mode=2 (timer). The time each completion event must wait.
57 57
58submit_queues=[0..nr_cpus]: 58submit_queues=[0..nr_cpus]:
59 The number of submission queues attached to the device driver. If unset, it 59 The number of submission queues attached to the device driver. If unset, it
60 defaults to 1 on single-queue and bio-based instances. For multi-queue, 60 defaults to 1 on single-queue and bio-based instances. For multi-queue,
61 its ignored when use_per_node_hctx module parameter is 1. 61 it is ignored when use_per_node_hctx module parameter is 1.
62 62
63hw_queue_depth=[0..qdepth]: Defaults: 64 63hw_queue_depth=[0..qdepth]: Default: 64
64 The hardware queue depth of the device. 64 The hardware queue depth of the device.
65 65
66III: Multi-queue specific parameters 66III: Multi-queue specific parameters
67 67
68use_per_node_hctx=[0/1]: Defaults: 1 68use_per_node_hctx=[0/1]: Default: 1
69 If 1, the multi-queue block layer is instantiated with a hardware dispatch 69 If 1, the multi-queue block layer is instantiated with a hardware dispatch
70 queue for each CPU node in the system. If 0, it is instantiated with the 70 queue for each CPU node in the system. If 0, it is instantiated with the
71 number of queues defined in the submit_queues parameter. 71 number of queues defined in the submit_queues parameter.