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-rw-r--r--block/Kconfig.iosched43
1 files changed, 24 insertions, 19 deletions
diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 7e803fc8..b71abfb 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -12,24 +12,14 @@ config IOSCHED_NOOP
that do their own scheduling and require only minimal assistance from
the kernel.
-config IOSCHED_AS
- tristate "Anticipatory I/O scheduler"
- default y
- ---help---
- The anticipatory I/O scheduler is generally a good choice for most
- environments, but is quite large and complex when compared to the
- deadline I/O scheduler, it can also be slower in some cases
- especially some database loads.
-
config IOSCHED_DEADLINE
tristate "Deadline I/O scheduler"
default y
---help---
- The deadline I/O scheduler is simple and compact, and is often as
- good as the anticipatory I/O scheduler, and in some database
- workloads, better. In the case of a single process performing I/O to
- a disk at any one time, its behaviour is almost identical to the
- anticipatory I/O scheduler and so is a good choice.
+ 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"
@@ -37,9 +27,28 @@ config IOSCHED_CFQ
---help---
The CFQ I/O scheduler tries to distribute bandwidth equally
among all processes in the system. It should provide a fair
- working environment, suitable for desktop systems.
+ 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 && CGROUPS
+ select BLK_CGROUP
+ default n
+ ---help---
+ Enable group IO scheduling in CFQ.
+
+config DEBUG_CFQ_IOSCHED
+ bool "Debug CFQ Scheduling"
+ depends on CFQ_GROUP_IOSCHED
+ select DEBUG_BLK_CGROUP
+ default n
+ ---help---
+ Enable CFQ IO scheduling debugging in CFQ. Currently it makes
+ blktrace output more verbose.
+
choice
prompt "Default I/O scheduler"
default DEFAULT_CFQ
@@ -47,9 +56,6 @@ choice
Select the I/O scheduler which will be used by default for all
block devices.
- config DEFAULT_AS
- bool "Anticipatory" if IOSCHED_AS=y
-
config DEFAULT_DEADLINE
bool "Deadline" if IOSCHED_DEADLINE=y
@@ -63,7 +69,6 @@ endchoice
config DEFAULT_IOSCHED
string
- default "anticipatory" if DEFAULT_AS
default "deadline" if DEFAULT_DEADLINE
default "cfq" if DEFAULT_CFQ
default "noop" if DEFAULT_NOOP
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