1# SPDX-License-Identifier: GPL-2.0 2if BLOCK 3 4menu "IO Schedulers" 5 6config IOSCHED_NOOP 7 bool 8 default y 9 ---help--- 10 The no-op I/O scheduler is a minimal scheduler that does basic merging 11 and sorting. Its main uses include non-disk based block devices like 12 memory devices, and specialised software or hardware environments 13 that do their own scheduling and require only minimal assistance from 14 the kernel. 15 16config IOSCHED_DEADLINE 17 tristate "Deadline I/O scheduler" 18 default y 19 ---help--- 20 The deadline I/O scheduler is simple and compact. It will provide 21 CSCAN service with FIFO expiration of requests, switching to 22 a new point in the service tree and doing a batch of IO from there 23 in case of expiry. 24 25config IOSCHED_CFQ 26 tristate "CFQ I/O scheduler" 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 36config CFQ_GROUP_IOSCHED 37 bool "CFQ Group Scheduling support" 38 depends on IOSCHED_CFQ && BLK_CGROUP 39 default n 40 ---help--- 41 Enable group IO scheduling in CFQ. 42 43choice 44 45 prompt "Default I/O scheduler" 46 default DEFAULT_CFQ 47 help 48 Select the I/O scheduler which will be used by default for all 49 block devices. 50 51 config DEFAULT_DEADLINE 52 bool "Deadline" if IOSCHED_DEADLINE=y 53 54 config DEFAULT_CFQ 55 bool "CFQ" if IOSCHED_CFQ=y 56 57 config DEFAULT_NOOP 58 bool "No-op" 59 60endchoice 61 62config DEFAULT_IOSCHED 63 string 64 default "deadline" if DEFAULT_DEADLINE 65 default "cfq" if DEFAULT_CFQ 66 default "noop" if DEFAULT_NOOP 67 68config MQ_IOSCHED_DEADLINE 69 tristate "MQ deadline I/O scheduler" 70 default y 71 ---help--- 72 MQ version of the deadline IO scheduler. 73 74config MQ_IOSCHED_KYBER 75 tristate "Kyber I/O scheduler" 76 default y 77 ---help--- 78 The Kyber I/O scheduler is a low-overhead scheduler suitable for 79 multiqueue and other fast devices. Given target latencies for reads and 80 synchronous writes, it will self-tune queue depths to achieve that 81 goal. 82 83config IOSCHED_BFQ 84 tristate "BFQ I/O scheduler" 85 default n 86 ---help--- 87 BFQ I/O scheduler for BLK-MQ. BFQ distributes the bandwidth of 88 of the device among all processes according to their weights, 89 regardless of the device parameters and with any workload. It 90 also guarantees a low latency to interactive and soft 91 real-time applications. Details in 92 Documentation/block/bfq-iosched.txt 93 94config BFQ_GROUP_IOSCHED 95 bool "BFQ hierarchical scheduling support" 96 depends on IOSCHED_BFQ && BLK_CGROUP 97 default n 98 ---help--- 99 100 Enable hierarchical scheduling in BFQ, using the blkio 101 (cgroups-v1) or io (cgroups-v2) controller. 102 103endmenu 104 105endif 106