path: root/block/Kconfig.iosched
diff options
authorJens Axboe <jens.axboe@oracle.com>2009-10-03 09:37:51 +0200
committerJens Axboe <jens.axboe@oracle.com>2009-10-03 09:37:51 +0200
commit492af6350a5ccf087e4964104a276ed358811458 (patch)
tree81d6398597758f5b712e1f47a3f24f0da66127ba /block/Kconfig.iosched
parent6a0afdf58d40200abd0c717261d1bc4c49195c2f (diff)
block: remove the anticipatory IO scheduler
AS is mostly a subset of CFQ, so there's little point in still providing this separate IO scheduler. Hopefully at some point we can get down to one single IO scheduler again, at least this brings us closer by having only one intelligent IO scheduler. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/Kconfig.iosched')
1 files changed, 4 insertions, 18 deletions
diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 7e803fc8877..baad3dae365 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.
tristate "Deadline I/O scheduler"
default y
- 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.
tristate "CFQ I/O scheduler"
@@ -47,9 +37,6 @@ 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
bool "Deadline" if IOSCHED_DEADLINE=y
@@ -63,7 +50,6 @@ endchoice
- default "anticipatory" if DEFAULT_AS
default "deadline" if DEFAULT_DEADLINE
default "cfq" if DEFAULT_CFQ
default "noop" if DEFAULT_NOOP