[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Deadline as default scheduler?



On Tue, 2010-08-10 at 00:04 +0200, Cesare Leonardi wrote:
> Hi all.
> 
> I've noted some changes in the scheduler configuration of 
> 2.6.35-trunk-686 and i wonder if they are erroneous or not, since their 
> effect are rather evident and i've seen no discussion on d-k.
> I was filing a bug but i preferred to ask on the mailing list first.
> 
> --- /boot/config-2.6.35-rc6-686 2010-07-26 13:09:56.000000000 +0200
> +++ /boot/config-2.6.35-trunk-686   2010-08-06 18:13:52.000000000 +0200
> @@ -221,11 +222,12 @@
>   #
>   CONFIG_IOSCHED_NOOP=y
>   CONFIG_IOSCHED_DEADLINE=y
> -CONFIG_IOSCHED_CFQ=y
> -# CONFIG_DEFAULT_DEADLINE is not set
> -CONFIG_DEFAULT_CFQ=y
> +CONFIG_IOSCHED_CFQ=m
> +CONFIG_CFQ_GROUP_IOSCHED=y
> +CONFIG_DEFAULT_DEADLINE=y
> +# CONFIG_DEFAULT_CFQ is not set
>   # CONFIG_DEFAULT_NOOP is not set
> -CONFIG_DEFAULT_IOSCHED="cfq"
> +CONFIG_DEFAULT_IOSCHED="deadline"
> 
> Why setting deadline as default scheduler? And why configuring cfq as 
> module?

This is due to enabling BLK_CGROUP:

config IOSCHED_CFQ
	tristate "CFQ I/O scheduler"
	# If BLK_CGROUP is a module, CFQ has to be built as module.
	depends on (BLK_CGROUP=m && m) || !BLK_CGROUP || BLK_CGROUP=y

Max, we have to make BLK_CGROUP=y or disable it completely.

Ben.

-- 
Ben Hutchings
Once a job is fouled up, anything done to improve it makes it worse.

Attachment: signature.asc
Description: This is a digitally signed message part


Reply to: