Re: ACPI throttling changes

On Tue, 9 Dec 2003 17:57:53 -0800 (PST)
Nate Lawson <nate_at_root.org> wrote:

> I'm working on a shared CPU frequency control driver.  One step is to
> remove some of the autonomy of the throttling portion of acpi_cpu.
> Please test this patch if you have a machine which supports throttling.
> With this patch, throttling can be changed by doing:
> 
>    sysctl hw.acpi.cpu.current_speed=X
> 
> where X is some number between 1 and hw.acpi.cpu.max_speed.  It is no
> longer driven by AC line transitions.  Run a CPU benchmark like this one
> to make sure the throttling transition still works with this patch.
> 
>     dd if=/dev/zero bs=1m count=500 | md5
> 
> This is part of a larger work.  Don't worry, it won't be committed until
> general CPU frequency control is done so no loss of functionality will be
> committed.
> 
> -Nate

I do not know if it's still of any use (I just caught up on my reading), 
but for whatever it worth, results are below. To be fair results are a 
little bit surprising to myself as I "feel" better response with 'economy'
set to 4 then with 'economy' set to 2, but of course this in unscientific.

I'm running -CURRENT from yesterday + this patch + my patch for picking PCI
IRQ, but the latter shoud not impact performance in any way shape or form.

Please, let me know if there is any additional information I can provide or 
if there any other things you want me to test here.


Trottling to 1
hw.acpi.cpu.current_speed: 8 -> 1
104857600 bytes transferred in 8.961181 secs (11701315 bytes/sec)
    9.17s real     6.21s user     2.70s system
Trottling to 2
hw.acpi.cpu.current_speed: 1 -> 2
104857600 bytes transferred in 8.987054 secs (11667628 bytes/sec)
    9.05s real     6.20s user     2.75s system
Trottling to 3
hw.acpi.cpu.current_speed: 2 -> 3
104857600 bytes transferred in 8.983341 secs (11672450 bytes/sec)
    9.05s real     6.08s user     2.83s system
Trottling to 4
hw.acpi.cpu.current_speed: 3 -> 4
104857600 bytes transferred in 9.006142 secs (11642899 bytes/sec)
    9.07s real     6.17s user     2.78s system
Trottling to 5
hw.acpi.cpu.current_speed: 4 -> 5
104857600 bytes transferred in 8.984664 secs (11670731 bytes/sec)
    9.05s real     6.25s user     2.68s system
Trottling to 6
hw.acpi.cpu.current_speed: 5 -> 6
104857600 bytes transferred in 8.986324 secs (11668575 bytes/sec)
    9.05s real     6.12s user     2.82s system
Trottling to 7
hw.acpi.cpu.current_speed: 6 -> 7
104857600 bytes transferred in 8.989106 secs (11664964 bytes/sec)
    9.06s real     6.23s user     2.72s system
Trottling to 8
hw.acpi.cpu.current_speed: 7 -> 8
104857600 bytes transferred in 7.827533 secs (13395996 bytes/sec)
    7.89s real     5.36s user     2.43s system