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
15 tristate "Anticipatory I/O scheduler"
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.
23 config IOSCHED_DEADLINE
24 tristate "Deadline I/O scheduler"
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.
34 tristate "CFQ I/O scheduler"
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.
42 prompt "Default I/O scheduler"
45 Select the I/O scheduler which will be used by default for all
49 bool "Anticipatory" if IOSCHED_AS=y
51 config DEFAULT_DEADLINE
52 bool "Deadline" if IOSCHED_DEADLINE=y
55 bool "CFQ" if IOSCHED_CFQ=y
62 config DEFAULT_IOSCHED
64 default "anticipatory" if DEFAULT_AS
65 default "deadline" if DEFAULT_DEADLINE
66 default "cfq" if DEFAULT_CFQ
67 default "noop" if DEFAULT_NOOP