Linux kernel development

Comrade DOS | 23 May 2012 21:12

PROBLEM: Performance drop

PROBLEM: Performance drop

After the release of linux 3.4.0 I've updated the kernel on all my machines.
In most of the computer upgrade was successful.
However, on my old laptop (HP Compaq 6715b) after the upgrade was just
impossible to work.
I found that CPU frequency scaling no longer work properly on this machine.
After loading the CPU clock is reset to the minimum (800 MHz), and
remains so until you reboot.
Changing the type of governor is not helping.
Recompile the kernel without CPU frequency scaling has been to solve
the problem, but even after this performance leaves much to be desired
(although, according to /proc/cpuinfo CPU frequency set maximum).
In addition to the above-described problems, there is another - the
problem with rebooting and shutting down (and possibly also have a
problem with s2ram and/or s2disk, but I'm their functionality I have
not tested).
If you try to shut down or restart the laptop it hangs.

Information about my system (according to
http://kernel.org/pub/linux/docs/lkml/reporting-bugs.html):

/proc/version
Linux version 3.4.0 (root <at> dos) (gcc version 4.6.3 (Gentoo 4.6.3 p1.0,
pie-0.5.1) ) #1 SMP PREEMPT Thu May 24 01:02:36 OMST 2012

ver_linux
Linux dos 3.4.0 #1 SMP PREEMPT Thu May 24 01:02:36 OMST 2012 x86_64
Mobile AMD Sempron(tm) Processor 3800+ AuthenticAMD GNU/Linux

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headers

Andreas Herrmann | 24 May 2012 14:31

Re: PROBLEM: Performance drop

On Thu, May 24, 2012 at 02:12:39AM +0700, Comrade DOS wrote:
> PROBLEM: Performance drop
> 
> After the release of linux 3.4.0 I've updated the kernel on all my machines.
> In most of the computer upgrade was successful.
> However, on my old laptop (HP Compaq 6715b) after the upgrade was just
> impossible to work.
> I found that CPU frequency scaling no longer work properly on this machine.
> After loading the CPU clock is reset to the minimum (800 MHz), and
> remains so until you reboot.
> Changing the type of governor is not helping.
> Recompile the kernel without CPU frequency scaling has been to solve
> the problem, but even after this performance leaves much to be desired
> (although, according to /proc/cpuinfo CPU frequency set maximum).
> In addition to the above-described problems, there is another - the
> problem with rebooting and shutting down (and possibly also have a
> problem with s2ram and/or s2disk, but I'm their functionality I have
> not tested).
> If you try to shut down or restart the laptop it hangs.

This somehow reminds me of commit
26adcfbf00e0726b4469070aa2f530dcf963f484 (x86: SB600: skip ACPI IRQ0
override if it is not routed to INT2 of IOAPIC).

See also
https://bugzilla.kernel.org/show_bug.cgi?id=11715 and
https://bugzilla.kernel.org/show_bug.cgi?id=11516

Question is why the quirk doesn't work (anymore) on your system.

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