| if BLOCK | 
 |  | 
 | 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_DEADLINE | 
 | 	tristate "Deadline I/O scheduler" | 
 | 	default y | 
 | 	---help--- | 
 | 	  The deadline I/O scheduler is simple and compact. It will provide | 
 | 	  CSCAN service with FIFO expiration of requests, switching to | 
 | 	  a new point in the service tree and doing a batch of IO from there | 
 | 	  in case of expiry. | 
 |  | 
 | 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 | 
 | 	  and low latency working environment, suitable for both desktop | 
 | 	  and server systems. | 
 |  | 
 | 	  This is the default I/O scheduler. | 
 |  | 
 | config CFQ_GROUP_IOSCHED | 
 | 	bool "CFQ Group Scheduling support" | 
 | 	depends on IOSCHED_CFQ && BLK_CGROUP | 
 | 	default n | 
 | 	---help--- | 
 | 	  Enable group IO scheduling in CFQ. | 
 |  | 
 | choice | 
 | 	prompt "Default I/O scheduler" | 
 | 	default DEFAULT_CFQ | 
 | 	help | 
 | 	  Select the I/O scheduler which will be used by default for all | 
 | 	  block devices. | 
 |  | 
 | 	config DEFAULT_DEADLINE | 
 | 		bool "Deadline" if IOSCHED_DEADLINE=y | 
 |  | 
 | 	config DEFAULT_CFQ | 
 | 		bool "CFQ" if IOSCHED_CFQ=y | 
 |  | 
 | 	config DEFAULT_NOOP | 
 | 		bool "No-op" | 
 |  | 
 | endchoice | 
 |  | 
 | config DEFAULT_IOSCHED | 
 | 	string | 
 | 	default "deadline" if DEFAULT_DEADLINE | 
 | 	default "cfq" if DEFAULT_CFQ | 
 | 	default "noop" if DEFAULT_NOOP | 
 |  | 
 | endmenu | 
 |  | 
 | endif |