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         select BLK_CGROUP
  27         default y
  28         ---help---
  29           The CFQ I/O scheduler tries to distribute bandwidth equally
  30           among all processes in the system. It should provide a fair
  31           and low latency working environment, suitable for both desktop
  32           and server systems.
  33
  34           This is the default I/O scheduler.
  35
  36 choice
  37         prompt "Default I/O scheduler"
  38         default DEFAULT_CFQ
  39         help
  40           Select the I/O scheduler which will be used by default for all
  41           block devices.
  42
  43         config DEFAULT_DEADLINE
  44                 bool "Deadline" if IOSCHED_DEADLINE=y
  45
  46         config DEFAULT_CFQ
  47                 bool "CFQ" if IOSCHED_CFQ=y
  48
  49         config DEFAULT_NOOP
  50                 bool "No-op"
  51
  52 endchoice
  53
  54 config DEFAULT_IOSCHED
  55         string
  56         default "deadline" if DEFAULT_DEADLINE
  57         default "cfq" if DEFAULT_CFQ
  58         default "noop" if DEFAULT_NOOP
  59
  60 endmenu
  61
  62 endif