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 35config CFQ_GROUP_IOSCHED 36 bool "CFQ Group Scheduling support" 37 depends on IOSCHED_CFQ && BLK_CGROUP 38 default n 39 ---help--- 40 Enable group IO scheduling in CFQ. 41 42choice 43 prompt "Default I/O scheduler" 44 default DEFAULT_CFQ 45 help 46 Select the I/O scheduler which will be used by default for all 47 block devices. 48 49 config DEFAULT_DEADLINE 50 bool "Deadline" if IOSCHED_DEADLINE=y 51 52 config DEFAULT_CFQ 53 bool "CFQ" if IOSCHED_CFQ=y 54 55 config DEFAULT_NOOP 56 bool "No-op" 57 58endchoice 59 60config DEFAULT_IOSCHED 61 string 62 default "deadline" if DEFAULT_DEADLINE 63 default "cfq" if DEFAULT_CFQ 64 default "noop" if DEFAULT_NOOP 65 66endmenu 67 68endif 69