projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | |
| 2 | menu "IO Schedulers" | |
| 3 | ||
| 4 | config IOSCHED_NOOP | |
| 5 | bool | |
| 6 | default y | |
| 7 | ---help--- | |
| 8 | The no-op I/O scheduler is a minimal scheduler that does basic merging | |
| 9 | and sorting. Its main uses include non-disk based block devices like | |
| 10 | memory devices, and specialised software or hardware environments | |
| 11 | that do their own scheduling and require only minimal assistance from | |
| 12 | the kernel. | |
| 13 | ||
| 14 | config IOSCHED_AS | |
| 15 | tristate "Anticipatory I/O scheduler" | |
| 16 | default y | |
| 17 | ---help--- | |
| 18 | The anticipatory I/O scheduler is the default disk scheduler. It is | |
| 19 | generally a good choice for most environments, but is quite large and | |
| 20 | complex when compared to the deadline I/O scheduler, it can also be | |
| 21 | slower in some cases especially some database loads. | |
| 22 | ||
| 23 | config IOSCHED_DEADLINE | |
| 24 | tristate "Deadline I/O scheduler" | |
| 25 | default y | |
| 26 | ---help--- | |
| 27 | The deadline I/O scheduler is simple and compact, and is often as | |
| 28 | good as the anticipatory I/O scheduler, and in some database | |
| 29 | workloads, better. In the case of a single process performing I/O to | |
| 30 | a disk at any one time, its behaviour is almost identical to the | |
| 31 | anticipatory I/O scheduler and so is a good choice. | |
| 32 | ||
| 33 | config IOSCHED_CFQ | |
| 34 | tristate "CFQ I/O scheduler" | |
| 35 | default y | |
| 36 | ---help--- | |
| 37 | The CFQ I/O scheduler tries to distribute bandwidth equally | |
| 38 | among all processes in the system. It should provide a fair | |
| 39 | working environment, suitable for desktop systems. | |
| 40 | ||
| 131dda7f ND |
41 | choice |
| 42 | prompt "Default I/O scheduler" | |
| 43 | default DEFAULT_AS | |
| 44 | help | |
| 45 | Select the I/O scheduler which will be used by default for all | |
| 46 | block devices. | |
| 47 | ||
| 48 | config DEFAULT_AS | |
| 49 | bool "Anticipatory" if IOSCHED_AS | |
| 50 | ||
| 51 | config DEFAULT_DEADLINE | |
| 52 | bool "Deadline" if IOSCHED_DEADLINE | |
| 53 | ||
| 54 | config DEFAULT_CFQ | |
| 55 | bool "CFQ" if IOSCHED_CFQ | |
| 56 | ||
| 57 | config DEFAULT_NOOP | |
| 58 | bool "No-op" | |
| 59 | ||
| 60 | endchoice | |
| 61 | ||
| 62 | config DEFAULT_IOSCHED | |
| 63 | string | |
| 64 | default "anticipatory" if DEFAULT_AS | |
| 65 | default "deadline" if DEFAULT_DEADLINE | |
| 66 | default "cfq" if DEFAULT_CFQ | |
| 67 | default "noop" if DEFAULT_NOOP | |
| 68 | ||
| 1da177e4 | 69 | endmenu |