block/Kconfig.iosched

   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         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
  35 choice
  36         prompt "Default I/O scheduler"
  37         default DEFAULT_CFQ
  38         help
  39           Select the I/O scheduler which will be used by default for all
  40           block devices.
  41
  42         config DEFAULT_DEADLINE
  43                 bool "Deadline" if IOSCHED_DEADLINE=y
  44
  45         config DEFAULT_CFQ
  46                 bool "CFQ" if IOSCHED_CFQ=y
  47
  48         config DEFAULT_NOOP
  49                 bool "No-op"
  50
  51 endchoice
  52
  53 config DEFAULT_IOSCHED
  54         string
  55         default "deadline" if DEFAULT_DEADLINE
  56         default "cfq" if DEFAULT_CFQ
  57         default "noop" if DEFAULT_NOOP
  58
  59 endmenu
  60
  61 endif