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32e380aedc
Block cgroup core can be built as module; however, it isn't too useful
as blk-throttle can only be built-in and cfq-iosched is usually the
default built-in scheduler. Scheduled blkcg cleanup requires calling
into blkcg from block core. To simplify that, disallow building blkcg
as module by making CONFIG_BLK_CGROUP bool.
If building blkcg core as module really matters, which I doubt, we can
revisit it after blkcg API cleanup.
-v2: Vivek pointed out that IOSCHED_CFQ was incorrectly updated to
depend on BLK_CGROUP. Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
68 lines
1.6 KiB
Text
68 lines
1.6 KiB
Text
if BLOCK
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menu "IO Schedulers"
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config IOSCHED_NOOP
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bool
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default y
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---help---
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The no-op I/O scheduler is a minimal scheduler that does basic merging
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and sorting. Its main uses include non-disk based block devices like
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memory devices, and specialised software or hardware environments
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that do their own scheduling and require only minimal assistance from
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the kernel.
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config IOSCHED_DEADLINE
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tristate "Deadline I/O scheduler"
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default y
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---help---
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The deadline I/O scheduler is simple and compact. It will provide
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CSCAN service with FIFO expiration of requests, switching to
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a new point in the service tree and doing a batch of IO from there
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in case of expiry.
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config IOSCHED_CFQ
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tristate "CFQ I/O scheduler"
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default y
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---help---
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The CFQ I/O scheduler tries to distribute bandwidth equally
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among all processes in the system. It should provide a fair
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and low latency working environment, suitable for both desktop
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and server systems.
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This is the default I/O scheduler.
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config CFQ_GROUP_IOSCHED
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bool "CFQ Group Scheduling support"
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depends on IOSCHED_CFQ && BLK_CGROUP
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default n
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---help---
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Enable group IO scheduling in CFQ.
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choice
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prompt "Default I/O scheduler"
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default DEFAULT_CFQ
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help
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Select the I/O scheduler which will be used by default for all
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block devices.
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config DEFAULT_DEADLINE
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bool "Deadline" if IOSCHED_DEADLINE=y
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config DEFAULT_CFQ
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bool "CFQ" if IOSCHED_CFQ=y
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config DEFAULT_NOOP
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bool "No-op"
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endchoice
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config DEFAULT_IOSCHED
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string
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default "deadline" if DEFAULT_DEADLINE
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default "cfq" if DEFAULT_CFQ
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default "noop" if DEFAULT_NOOP
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endmenu
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endif
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