Re: sched domains oddness.

On Fri, Oct 31, 2008 at 01:17:21PM -0400, Dave Jones wrote:
On Fri, Oct 31, 2008 at 10:09:29AM -0700, Suresh Siddha wrote:

> > looks like someone is triggering rebuild_sched_domains(), is something
> > poking cpusetfs files or flipping between sched_mc settings?
>
> I remember someone mentioning that some distro's started setting
> sched_mc_power_savings to '1' by default during boot. On a dual-core
> laptop, this will not give any advantage.
>
> I have to fix the code to not export this tunable, when we have only
> socket in the system.
>
> Dave, Is your distro also setting this tunable blindly during boot :(

(13:15:25:davej@vaio:~)$ cat /sys/devices/system/cpu/sched_mc_power_savings
0

So no, unless something set it to 1, and then back to 0.

A grep of etc shows up nothing in initscripts. Does hal or something
play with this?

Even curiouser.. When I unplug AC and replug it, it happens again, but slightly
differently..

CPU0 attaching NULL sched-domain.
CPU1 attaching NULL sched-domain.
CPU0 attaching sched-domain:
domain 0: span 0-1 level MC
groups: 0 1
domain 1: span 0-1 level CPU
groups: 0-1
domain 2: span 0-1 level NODE
groups: 0-1
CPU1 attaching sched-domain:
domain 0: span 0-1 level MC
groups: 1 0
domain 1: span 0-1 level CPU
groups: 0-1
domain 2: span 0-1 level NODE
groups: 0-1
CPU0 attaching NULL sched-domain.
CPU1 attaching NULL sched-domain.
CPU0 attaching sched-domain:
domain 0: span 0-1 level MC
groups: 0 1
domain 1: span 0-1 level NODE
groups: 0-1
CPU1 attaching sched-domain:
domain 0: span 0-1 level MC
groups: 1 0
domain 1: span 0-1 level NODE
groups: 0-1


Note how the CPU level doesn't show up in the 2nd case.

This still doesn't explain the flip-flop I saw just from booting,
as that was on AC the whole time.

I grepped hal and gnome-power-manager, and didn't see anything
touching sched_mc

Dave

--
http://www.codemonkey.org.uk
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Relevant Pages