13.1 and processor sleep states

[Chris Vine]

Hi,

This is a heads-up for anyone using Slackware 13.1 with an Atom and
possibly a Core 2 processor. 13.1 works fine on my computer with a
Pentium processor, but on my netbook with an Atom N270 processor I get
odd effects from the generic 2.6.33.4 x86 kernel during boot-up. The
processor appears to enter low power sleep states during boot-up,
particularly when waiting for events such as the network to come up,
which sometimes requires me to press a key on the keyboard in order to
trigger an interrupt which will wake it up again. It generally works
OK when a desktop environment such as KDE is running: that probably
never lets the processor enter any of its deep sleep states to allow
the problem to occur.

This is with the generic x86 huge-smp kernel (the kernel used during
installation). It is not particularly problematic: I have simply
recompiled the kernel for the Atom processor rather than generic x86 and
it works nicely.

The Core-2 processor has similar C-sleep states to the Atom, so that
may also be affected (I don't know).

Chris

[Grant]

I usually compile a kernel to suit the machine :) This is another reason
for doing do. Distro kernels need to be all things for all machines, thus
compromise best performance. That's true if it be Slackware or some other
flavour.

Grant.
--
http://bugs.id.au/

[Douglas Mayne]

I compiled 2.6.33.5 using my own slight variation from the Slackware 13.1
default as provided by the file, config-generic-smp-2.6.33.4-smp.

Mainly, I changed the minimum processor level to Pentium III and removed
math emulation. That appears to have fixed the slight "freezes" that I
was occassionally seeing on an Atom N270 CPU. The operation is now much
smoother, and what I would expect with a box with 2G RAM. BTW, I compiled
for Pentium III to be able to reuse the kernel on some other older boxes
without recompiling.

--
Douglas Mayne