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 config CFQ_GROUP_IOSCHED
  36         bool "CFQ Group Scheduling support"
  37         depends on IOSCHED_CFQ && CGROUPS
  38         select BLK_CGROUP
  39         default n
  40         ---help---
  41           Enable group IO scheduling in CFQ.
  42
  43 choice
  44         prompt "Default I/O scheduler"
  45         default DEFAULT_CFQ
  46         help
  47           Select the I/O scheduler which will be used by default for all
  48           block devices.
  49
  50         config DEFAULT_DEADLINE
  51                 bool "Deadline" if IOSCHED_DEADLINE=y
  52
  53         config DEFAULT_CFQ
  54                 bool "CFQ" if IOSCHED_CFQ=y
  55
  56         config DEFAULT_NOOP
  57                 bool "No-op"
  58
  59 endchoice
  60
  61 config DEFAULT_IOSCHED
  62         string
  63         default "deadline" if DEFAULT_DEADLINE
  64         default "cfq" if DEFAULT_CFQ
  65         default "noop" if DEFAULT_NOOP
  66
  67 endmenu
  68
  69 endif