1if BLOCK 2 3menu "IO Schedulers" 4 5config 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 15config 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 24config 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 35choice 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 51endchoice 52 53config DEFAULT_IOSCHED 54 string 55 default "deadline" if DEFAULT_DEADLINE 56 default "cfq" if DEFAULT_CFQ 57 default "noop" if DEFAULT_NOOP 58 59endmenu 60 61endif 62