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Commit | Line | Data |
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1 | if BLOCK | |
2 | ||
3 | menu "IO Schedulers" | |
4 | ||
5 | config 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 | ||
15 | config 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 | ||
24 | config IOSCHED_CFQ | |
25 | tristate "CFQ I/O scheduler" | |
26 | # If BLK_CGROUP is a module, CFQ has to be built as module. | |
27 | depends on (BLK_CGROUP=m && m) || !BLK_CGROUP || BLK_CGROUP=y | |
28 | default y | |
29 | ---help--- | |
30 | The CFQ I/O scheduler tries to distribute bandwidth equally | |
31 | among all processes in the system. It should provide a fair | |
32 | and low latency working environment, suitable for both desktop | |
33 | and server systems. | |
34 | ||
35 | This is the default I/O scheduler. | |
36 | ||
37 | Note: If BLK_CGROUP=m, then CFQ can be built only as module. | |
38 | ||
39 | config CFQ_GROUP_IOSCHED | |
40 | bool "CFQ Group Scheduling support" | |
41 | depends on IOSCHED_CFQ && BLK_CGROUP | |
42 | default n | |
43 | ---help--- | |
44 | Enable group IO scheduling in CFQ. | |
45 | ||
46 | choice | |
47 | prompt "Default I/O scheduler" | |
48 | default DEFAULT_CFQ | |
49 | help | |
50 | Select the I/O scheduler which will be used by default for all | |
51 | block devices. | |
52 | ||
53 | config DEFAULT_DEADLINE | |
54 | bool "Deadline" if IOSCHED_DEADLINE=y | |
55 | ||
56 | config DEFAULT_CFQ | |
57 | bool "CFQ" if IOSCHED_CFQ=y | |
58 | ||
59 | config DEFAULT_NOOP | |
60 | bool "No-op" | |
61 | ||
62 | endchoice | |
63 | ||
64 | config DEFAULT_IOSCHED | |
65 | string | |
66 | default "deadline" if DEFAULT_DEADLINE | |
67 | default "cfq" if DEFAULT_CFQ | |
68 | default "noop" if DEFAULT_NOOP | |
69 | ||
70 | endmenu | |
71 | ||
72 | endif |