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1 if BLOCK
2
3 menu "IO Schedulers"
4
5 config 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
15 config 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
24 config 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
35 config 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
42 choice
43
44 prompt "Default I/O scheduler"
45 default DEFAULT_CFQ
46 help
47 Select the I/O scheduler which will be used by default for all
48 block devices.
49
50 config DEFAULT_DEADLINE
51 bool "Deadline" if IOSCHED_DEADLINE=y
52
53 config DEFAULT_CFQ
54 bool "CFQ" if IOSCHED_CFQ=y
55
56 config DEFAULT_NOOP
57 bool "No-op"
58
59 endchoice
60
61 config DEFAULT_IOSCHED
62 string
63 default "deadline" if DEFAULT_DEADLINE
64 default "cfq" if DEFAULT_CFQ
65 default "noop" if DEFAULT_NOOP
66
67 config MQ_IOSCHED_DEADLINE
68 tristate "MQ deadline I/O scheduler"
69 default y
70 ---help---
71 MQ version of the deadline IO scheduler.
72
73 config MQ_IOSCHED_KYBER
74 tristate "Kyber I/O scheduler"
75 default y
76 ---help---
77 The Kyber I/O scheduler is a low-overhead scheduler suitable for
78 multiqueue and other fast devices. Given target latencies for reads and
79 synchronous writes, it will self-tune queue depths to achieve that
80 goal.
81
82 config IOSCHED_BFQ
83 tristate "BFQ I/O scheduler"
84 default n
85 ---help---
86 BFQ I/O scheduler for BLK-MQ. BFQ distributes the bandwidth of
87 of the device among all processes according to their weights,
88 regardless of the device parameters and with any workload. It
89 also guarantees a low latency to interactive and soft
90 real-time applications. Details in
91 Documentation/block/bfq-iosched.txt
92
93 config BFQ_GROUP_IOSCHED
94 bool "BFQ hierarchical scheduling support"
95 depends on IOSCHED_BFQ && BLK_CGROUP
96 default n
97 ---help---
98
99 Enable hierarchical scheduling in BFQ, using the blkio
100 (cgroups-v1) or io (cgroups-v2) controller.
101
102 endmenu
103
104 endif