swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: 3eb2ce825ea1ad89d20f7a3b5780df850e4be274 authored by Linus Torvalds on 25 March 2018, 22:44:30 UTC
Linux 4.16-rc7
Linux 4.16-rc7
Tip revision: 3eb2ce8
Kconfig.iosched
# SPDX-License-Identifier: GPL-2.0
if BLOCK
menu "IO Schedulers"
config IOSCHED_NOOP
bool
default y
---help---
The no-op I/O scheduler is a minimal scheduler that does basic merging
and sorting. Its main uses include non-disk based block devices like
memory devices, and specialised software or hardware environments
that do their own scheduling and require only minimal assistance from
the kernel.
config IOSCHED_DEADLINE
tristate "Deadline I/O scheduler"
default y
---help---
The deadline I/O scheduler is simple and compact. It will provide
CSCAN service with FIFO expiration of requests, switching to
a new point in the service tree and doing a batch of IO from there
in case of expiry.
config IOSCHED_CFQ
tristate "CFQ I/O scheduler"
default y
---help---
The CFQ I/O scheduler tries to distribute bandwidth equally
among all processes in the system. It should provide a fair
and low latency working environment, suitable for both desktop
and server systems.
This is the default I/O scheduler.
config CFQ_GROUP_IOSCHED
bool "CFQ Group Scheduling support"
depends on IOSCHED_CFQ && BLK_CGROUP
default n
---help---
Enable group IO scheduling in CFQ.
choice
prompt "Default I/O scheduler"
default DEFAULT_CFQ
help
Select the I/O scheduler which will be used by default for all
block devices.
config DEFAULT_DEADLINE
bool "Deadline" if IOSCHED_DEADLINE=y
config DEFAULT_CFQ
bool "CFQ" if IOSCHED_CFQ=y
config DEFAULT_NOOP
bool "No-op"
endchoice
config DEFAULT_IOSCHED
string
default "deadline" if DEFAULT_DEADLINE
default "cfq" if DEFAULT_CFQ
default "noop" if DEFAULT_NOOP
config MQ_IOSCHED_DEADLINE
tristate "MQ deadline I/O scheduler"
default y
---help---
MQ version of the deadline IO scheduler.
config MQ_IOSCHED_KYBER
tristate "Kyber I/O scheduler"
default y
---help---
The Kyber I/O scheduler is a low-overhead scheduler suitable for
multiqueue and other fast devices. Given target latencies for reads and
synchronous writes, it will self-tune queue depths to achieve that
goal.
config IOSCHED_BFQ
tristate "BFQ I/O scheduler"
default n
---help---
BFQ I/O scheduler for BLK-MQ. BFQ distributes the bandwidth of
of the device among all processes according to their weights,
regardless of the device parameters and with any workload. It
also guarantees a low latency to interactive and soft
real-time applications. Details in
Documentation/block/bfq-iosched.txt
config BFQ_GROUP_IOSCHED
bool "BFQ hierarchical scheduling support"
depends on IOSCHED_BFQ && BLK_CGROUP
default n
---help---
Enable hierarchical scheduling in BFQ, using the blkio
(cgroups-v1) or io (cgroups-v2) controller.
endmenu
endif