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 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 36choice 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 52endchoice 53 54config DEFAULT_IOSCHED 55 string 56 default "deadline" if DEFAULT_DEADLINE 57 default "cfq" if DEFAULT_CFQ 58 default "noop" if DEFAULT_NOOP 59 60endmenu 61 62endif 63