kconfig.iosched

Linux块设备驱动源码

menu "IO Schedulers"

config IOSCHED_NOOP
	bool
	default y
	---help---
	  The no-op I/O scheduler is a minimal scheduler that does basic merging
	  and sorting. Its main uses include non-disk based block devices like
	  memory devices, and specialised software or hardware environments
	  that do their own scheduling and require only minimal assistance from
	  the kernel.

config IOSCHED_AS
	tristate "Anticipatory I/O scheduler"
	default y
	---help---
	  The anticipatory I/O scheduler is the default disk scheduler. It is
	  generally a good choice for most environments, but is quite large and
	  complex when compared to the deadline I/O scheduler, it can also be
	  slower in some cases especially some database loads.

config IOSCHED_DEADLINE
	tristate "Deadline I/O scheduler"
	default y
	---help---
	  The deadline I/O scheduler is simple and compact, and is often as
	  good as the anticipatory I/O scheduler, and in some database
	  workloads, better. In the case of a single process performing I/O to
	  a disk at any one time, its behaviour is almost identical to the
	  anticipatory I/O scheduler and so is a good choice.

config IOSCHED_CFQ
	tristate "CFQ I/O scheduler"
	default y
	---help---
	  The CFQ I/O scheduler tries to distribute bandwidth equally
	  among all processes in the system. It should provide a fair
	  working environment, suitable for desktop systems.

endmenu