19361401eSDavid Howellsif BLOCK 21da177e4SLinus Torvalds 31da177e4SLinus Torvaldsmenu "IO Schedulers" 41da177e4SLinus Torvalds 51da177e4SLinus Torvaldsconfig IOSCHED_NOOP 61da177e4SLinus Torvalds bool 71da177e4SLinus Torvalds default y 81da177e4SLinus Torvalds ---help--- 91da177e4SLinus Torvalds The no-op I/O scheduler is a minimal scheduler that does basic merging 101da177e4SLinus Torvalds and sorting. Its main uses include non-disk based block devices like 111da177e4SLinus Torvalds memory devices, and specialised software or hardware environments 121da177e4SLinus Torvalds that do their own scheduling and require only minimal assistance from 131da177e4SLinus Torvalds the kernel. 141da177e4SLinus Torvalds 151da177e4SLinus Torvaldsconfig IOSCHED_DEADLINE 161da177e4SLinus Torvalds tristate "Deadline I/O scheduler" 171da177e4SLinus Torvalds default y 181da177e4SLinus Torvalds ---help--- 19492af635SJens Axboe The deadline I/O scheduler is simple and compact. It will provide 20492af635SJens Axboe CSCAN service with FIFO expiration of requests, switching to 21492af635SJens Axboe a new point in the service tree and doing a batch of IO from there 22492af635SJens Axboe in case of expiry. 231da177e4SLinus Torvalds 241da177e4SLinus Torvaldsconfig IOSCHED_CFQ 251da177e4SLinus Torvalds tristate "CFQ I/O scheduler" 261da177e4SLinus Torvalds default y 271da177e4SLinus Torvalds ---help--- 281da177e4SLinus Torvalds The CFQ I/O scheduler tries to distribute bandwidth equally 291da177e4SLinus Torvalds among all processes in the system. It should provide a fair 3008dc8726SJens Axboe and low latency working environment, suitable for both desktop 3108dc8726SJens Axboe and server systems. 3208dc8726SJens Axboe 33a8e14b95SJesper Juhl This is the default I/O scheduler. 341da177e4SLinus Torvalds 3525bc6b07SVivek Goyalconfig CFQ_GROUP_IOSCHED 3625bc6b07SVivek Goyal bool "CFQ Group Scheduling support" 37*afc24d49SVivek Goyal depends on IOSCHED_CFQ && BLK_CGROUP 3825bc6b07SVivek Goyal default n 3925bc6b07SVivek Goyal ---help--- 4025bc6b07SVivek Goyal Enable group IO scheduling in CFQ. 4125bc6b07SVivek Goyal 42131dda7fSNate Dillerchoice 43131dda7fSNate Diller prompt "Default I/O scheduler" 44b17fd9bcSJens Axboe default DEFAULT_CFQ 45131dda7fSNate Diller help 46131dda7fSNate Diller Select the I/O scheduler which will be used by default for all 47131dda7fSNate Diller block devices. 48131dda7fSNate Diller 49131dda7fSNate Diller config DEFAULT_DEADLINE 50c6ea2ba7SJens Axboe bool "Deadline" if IOSCHED_DEADLINE=y 51131dda7fSNate Diller 52131dda7fSNate Diller config DEFAULT_CFQ 53c6ea2ba7SJens Axboe bool "CFQ" if IOSCHED_CFQ=y 54131dda7fSNate Diller 55131dda7fSNate Diller config DEFAULT_NOOP 56131dda7fSNate Diller bool "No-op" 57131dda7fSNate Diller 58131dda7fSNate Dillerendchoice 59131dda7fSNate Diller 60131dda7fSNate Dillerconfig DEFAULT_IOSCHED 61131dda7fSNate Diller string 62131dda7fSNate Diller default "deadline" if DEFAULT_DEADLINE 63131dda7fSNate Diller default "cfq" if DEFAULT_CFQ 64131dda7fSNate Diller default "noop" if DEFAULT_NOOP 65131dda7fSNate Diller 661da177e4SLinus Torvaldsendmenu 679361401eSDavid Howells 689361401eSDavid Howellsendif 69