freebsd stable - Feb 2006 - AMD Mobile Athlon 64 VERY slow on 6-STABLE and 7-CURRENT

This particular laptop, with a AMD Mobile Athlon 64 3000+
        processor and
        a MSI-made motherboard runs VERY SLOWLY with FreeBSD versions on
        the
        6-STABLE branch or 7-CURRENT branch.
        
        - This happens when running either the i386 architecture version
        or the amd64 architecture version. It is not specific of the
        amd64 version.
        - This happens with acpi either enabled or disabled, although
        results aren't exactly the same.
        - This happens with apic either enabled or disabled (on
        5.4-RELEASE,
        amd64 architecture, apic had to be disabled on this computer to
        avoid crash).
        - This machine is fine on 5-STABLE, including 5.5-BETA1.
        
        This is about CPU speed, it is most noted when generating a RSA
        key, for instance. I bothered use the dhrystone 2 benchmark
        (from unixbench) and the result is about 13000 dhrystones/sec
        with acpi enabled, and 38000 dhrystones/sec with acpi disabled.
        It should be above 5 million dhrystones/sec, the system is
        totally unusable, about as fast as a 386.
        
        This is not related to acpi sleep states or acpi throttle since
        it
        happens with acpi disabled.
        
        The brand of the laptop is Targa Traveller 826 (motherboard is
        MSI).
        I've tried everything I could, I couldn't yet discover some
        sysctl value that could make any difference, or even in what
        section of the kernel may the problem be.
        
        Has anyone ever had a similar problem?
        Any sugestions?
        
        I was hopping to narrow the circumstances of this problem before
        sending a pr.
        
        ----
        Miguel Ramos, miguel@anjos.strangled.net

Ter, 2006-02-14 ?s 13:16 +0000, David Malone escreveu:
> On Tue, Feb 14, 2006 at 01:00:40PM +0000, Miguel Ramos wrote:
> >         Any sugestions?
> 
> Check with vmstat -i to see if you have an interrupt storm of
> some sort.
> 
> 	David.
Very good sugestion, thank you, that is obviously it and it didn't cross
my mind.

It is on irq11 (devices cbb0, cardbus and ohci0++, whatever ++ is).
53000 interrupts per second... That might just slow down even an Athlon
64.
I'm going to disable cardbus first and then ohci. Isn't there a specific
command to keep an interrupt source quiet?

This should have crossed my mind. When I was a kid, in DOS days, I once
increased the clock tick rate on DOS with similar effects.

Good thing that witches don't exist. Felix qui potuit rerum cognoscere
causas.

Miguel

On Tuesday 14 February 2006 23:30, Miguel Ramos wrote:
>         Has anyone ever had a similar problem?
>         Any sugestions?
Might help if you sent a verbose boot dmesg and a copy of your kernel config 
(unless you're running GENERIC)

Are you using i386 or amd64?
What is the output of sysctl kern.timecounter and hw.acpi?

-- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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