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1if BLOCK
2
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
15config IOSCHED_DEADLINE
16	tristate "Deadline I/O scheduler"
17	default y
18	---help---
19	  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.
23
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
30	  and low latency working environment, suitable for both desktop
31	  and server systems.
32
33	  This is the default I/O scheduler.
34
35config CFQ_GROUP_IOSCHED
36	bool "CFQ Group Scheduling support"
37	depends on IOSCHED_CFQ && BLK_CGROUP
38	default n
39	---help---
40	  Enable group IO scheduling in CFQ.
41
42choice
43	prompt "Default I/O scheduler"
44	default DEFAULT_CFQ
45	help
46	  Select the I/O scheduler which will be used by default for all
47	  block devices.
48
49	config DEFAULT_DEADLINE
50		bool "Deadline" if IOSCHED_DEADLINE=y
51
52	config DEFAULT_CFQ
53		bool "CFQ" if IOSCHED_CFQ=y
54
55	config DEFAULT_NOOP
56		bool "No-op"
57
58endchoice
59
60config DEFAULT_IOSCHED
61	string
62	default "deadline" if DEFAULT_DEADLINE
63	default "cfq" if DEFAULT_CFQ
64	default "noop" if DEFAULT_NOOP
65
66endmenu
67
68endif
69