Re: Buildtime woes and other stuff
On Thursday 24 March 2005 10:36am, Oliver Korpilla wrote:
>
> > Your timing/clock problems are however more widespread. I have related
> > problems too with spurious messages about lost timer ticks. They all
> > appear
> > to stem from problems with the kernel's ACPI driver and/or the kernel not
> > handling a changing CPU clock speed well (this happens to me precisely
> > because I've got the Corecell activated on the mobo and its dynamically
> > changing the CPU speed based on load). I've seen one conversation on
> > lkml about it, and it appears to be a "work-in-progress" problem, that
> > will eventually be solved within the kernel itself.
>
> I would be perfectly fine with running with constant maximum speed, I want
> no changing clock speeds. May it be that the clock remains in "fast mode",
> while the CPU clock is reduced? This would explain the performance lags
> with kernel compiling!!!
No, the advantage of MSI's Corecell chip is that the whole process of driving
the CPU is done automatically on the motherboard. It is enabled in the
system BIOS, and is disabled by default, but you may want to check that.
There are 2 different things here though: Dynamic Overclocking (called
D.O.T. by MSI) and AMD's Cool-n-Quiet. The dynamic overclocking would never
cause your system to slow down, its the Cool-n-Quiet option that might do
that. But in both cases, AIUI, on an MSI mobo with an A64 with Cool-n-Quiet,
the CPU is being controlled entirely by the motherboard, so nothing in the
kernel (or any OS) should effect this (it could if ACPI were working, but you
already said that doesn't work). Note that I have both these functions
turned on, without difficulty. It slows down when idle, and speeds up under
heavy load, without the kernel having to know or do anything (my problem with
the 'lost ticks' may be the kernel trying to 'know' but not expecting the
CPU's clock to be dynamically driven by firmware on the motherboard).
So, are you using CPU Freq Scaling in the kernel? Have you tried turning all
that off?
Check your system BIOS and look for a 'Cool-n-Quiet' option in there
somewhere, and disable that to see if it helps. The DOT stuff is under
"Freq/Voltage Control" on my BIOS screen, but again that should be off by
default (assuming your system has it) and wouldn't slow your system down (if
its off try turning it on, and setting its controller to the 5% overclock
level - which should be safe - and see if that helps).
Check your process list before you compile, do you have any processes eating a
lot of CPU time? Try dropping into single user mode with as few other
processes running and see what your speed is like then. Your system has a
better CPU than mine, but is taking ~2.5 times longer than mine, so there has
to be some serious slowdown on your machine, either the CPU isn't running
full speed, or something is eating your CPU cycles.
In your system's boot up messages, that normally are captured by the dmesg
program, what is your bogomips reading? I know, its not useful for comparing
different kinds of CPUs, but since our CPUs are the same kind with yours just
being a later model, your bogomips reading should be significantly better
than mine.
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