On 2008.06.16 07:43:37 -0700, Arjan van de Ven wrote: > On Mon, 16 Jun 2008 12:42:00 +0200 > Pavel Machek <pavel@xxxxxxx> wrote: > > > On Sat 2008-06-07 14:54:35, Arjan van de Ven wrote: > > > On Sat, 7 Jun 2008 23:39:18 +0200 > > > Pavel Machek <pavel@xxxxxxx> wrote: > > > > > > > > # echo 1866000 > scaling_max_freq ; cat scaling_max_freq > > > > > 800000 > > > > > # echo 1866000 > scaling_max_freq ; cat scaling_max_freq > > > > > 800000 > > > > > > > > > > > > > > > This renders my Dothan to utterly poor speeds. (standard T43) > > > > > > > > > > performance cpufreq governor makes no difference - I still can't > > > > > change the frequency upper/lower values. > > > > > > > > Hmm, I have similar problem in Novell bugzilla, on very different > > > > hw: > > > > > > > > https://bugzilla.novell.com/show_bug.cgi?id=396311 > > > > > are either of you running gnome-power-manager or kpowersaved ? > > > sometimes these programs (and more likely, the patches added by a > > > distro maintainer who doesn't fully realize how power works) tend to > > > muck with kernel settings around CPU frequency that they have > > > absolutely no business touching... > > > > In novel bugzilla case ignore_ppc=1 helped, so it seems to be BIOS > > problem, not userland's... > > well as long as the user doesn't use this for production use... the > BIOS often reduces frequencies available to deal with thermal > situations, so it's not a good idea to ignore that. Yep, seems to be a thermal thing. I managed to find some time to play around with it a bit, and running a cpu hog for a short period of time, while watching temperature and scaling_max_freq showed this: cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 49 C cpufreq# cat scaling_max_freq 1866000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 51 C cpufreq# cat scaling_max_freq 1866000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 52 C cpufreq# cat scaling_max_freq 1866000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 53 C cpufreq# cat scaling_max_freq 1866000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 54 C cpufreq# cat scaling_max_freq 800000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 53 C cpufreq# cat scaling_max_freq 800000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 51 C cpufreq# cat scaling_max_freq 800000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 51 C cpufreq# cat scaling_max_freq 800000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 50 C cpufreq# cat scaling_max_freq 800000 cpufreq# cat /proc/acpi/thermal_zone/THM0/temperature temperature: 49 C cpufreq# cat scaling_max_freq 1866000 So upon reaching 54°C some throttling kicks in and only when going back to less then 50°C, that limit is lifted again. Too bad that with Linux, this T43 already runs at about 47°C when idle, so as soon as there's any load on the cpu, it will scale up for a few seconds and then get throttled :-( There's no userspace powersave foo involved here, just the plain ondemand scaling governor, same happens with the performance governor. Björn -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
