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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"
37 depends on IOSCHED_CFQ && CGROUPS
38 select BLK_CGROUP
39 default n
40 ---help---
41 Enable group IO scheduling in CFQ.
42
Vivek Goyal2868ef72009-12-03 12:59:48 -050043config DEBUG_CFQ_IOSCHED
44 bool "Debug CFQ Scheduling"
45 depends on CFQ_GROUP_IOSCHED
46 select DEBUG_BLK_CGROUP
47 default n
48 ---help---
49 Enable CFQ IO scheduling debugging in CFQ. Currently it makes
50 blktrace output more verbose.
51
Nate Diller131dda72005-10-30 15:02:19 -080052choice
53 prompt "Default I/O scheduler"
Jens Axboeb17fd9b2006-06-19 10:06:48 +020054 default DEFAULT_CFQ
Nate Diller131dda72005-10-30 15:02:19 -080055 help
56 Select the I/O scheduler which will be used by default for all
57 block devices.
58
Nate Diller131dda72005-10-30 15:02:19 -080059 config DEFAULT_DEADLINE
Jens Axboec6ea2ba2005-11-04 08:44:58 +010060 bool "Deadline" if IOSCHED_DEADLINE=y
Nate Diller131dda72005-10-30 15:02:19 -080061
62 config DEFAULT_CFQ
Jens Axboec6ea2ba2005-11-04 08:44:58 +010063 bool "CFQ" if IOSCHED_CFQ=y
Nate Diller131dda72005-10-30 15:02:19 -080064
65 config DEFAULT_NOOP
66 bool "No-op"
67
68endchoice
69
70config DEFAULT_IOSCHED
71 string
Nate Diller131dda72005-10-30 15:02:19 -080072 default "deadline" if DEFAULT_DEADLINE
73 default "cfq" if DEFAULT_CFQ
74 default "noop" if DEFAULT_NOOP
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076endmenu
David Howells93614012006-09-30 20:45:40 +020077
78endif