blob: 421bef9c4c48d26c035792716064e9f273253c6e [file] [log] [blame]
David Howells93614012006-09-30 20:45:40 +02001if BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -07002
3menu "IO Schedulers"
4
5config IOSCHED_NOOP
6 bool
7 default y
8 ---help---
9 The no-op I/O scheduler is a minimal scheduler that does basic merging
10 and sorting. Its main uses include non-disk based block devices like
11 memory devices, and specialised software or hardware environments
12 that do their own scheduling and require only minimal assistance from
13 the kernel.
14
Linus Torvalds1da177e2005-04-16 15:20:36 -070015config IOSCHED_DEADLINE
16 tristate "Deadline I/O scheduler"
17 default y
18 ---help---
Jens Axboe492af632009-10-03 09:37:51 +020019 The deadline I/O scheduler is simple and compact. It will provide
20 CSCAN service with FIFO expiration of requests, switching to
21 a new point in the service tree and doing a batch of IO from there
22 in case of expiry.
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
24config IOSCHED_CFQ
25 tristate "CFQ I/O scheduler"
26 default y
27 ---help---
28 The CFQ I/O scheduler tries to distribute bandwidth equally
29 among all processes in the system. It should provide a fair
Jens Axboe08dc8722009-10-03 09:40:47 +020030 and low latency working environment, suitable for both desktop
31 and server systems.
32
Jesper Juhla8e14b92007-02-17 20:08:22 +010033 This is the default I/O scheduler.
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Vivek Goyal25bc6b02009-12-03 12:59:43 -050035config CFQ_GROUP_IOSCHED
36 bool "CFQ Group Scheduling support"
Vivek Goyalafc24d42010-04-26 19:27:56 +020037 depends on IOSCHED_CFQ && BLK_CGROUP
Vivek Goyal25bc6b02009-12-03 12:59:43 -050038 default n
39 ---help---
40 Enable group IO scheduling in CFQ.
41
Nate Diller131dda72005-10-30 15:02:19 -080042choice
43 prompt "Default I/O scheduler"
Jens Axboeb17fd9b2006-06-19 10:06:48 +020044 default DEFAULT_CFQ
Nate Diller131dda72005-10-30 15:02:19 -080045 help
46 Select the I/O scheduler which will be used by default for all
47 block devices.
48
Nate Diller131dda72005-10-30 15:02:19 -080049 config DEFAULT_DEADLINE
Jens Axboec6ea2ba2005-11-04 08:44:58 +010050 bool "Deadline" if IOSCHED_DEADLINE=y
Nate Diller131dda72005-10-30 15:02:19 -080051
52 config DEFAULT_CFQ
Jens Axboec6ea2ba2005-11-04 08:44:58 +010053 bool "CFQ" if IOSCHED_CFQ=y
Nate Diller131dda72005-10-30 15:02:19 -080054
55 config DEFAULT_NOOP
56 bool "No-op"
57
58endchoice
59
60config DEFAULT_IOSCHED
61 string
Nate Diller131dda72005-10-30 15:02:19 -080062 default "deadline" if DEFAULT_DEADLINE
63 default "cfq" if DEFAULT_CFQ
64 default "noop" if DEFAULT_NOOP
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066endmenu
David Howells93614012006-09-30 20:45:40 +020067
68endif