Re: Switch APIC to driver model (and make S3 sleep with APIC on)

[John Levon <levon@movementarian.org>]

On Mon, Feb 03, 2003 at 04:40:08PM +0100, Pavel Machek wrote:

> should apt-get install

not packaged yet I'm afraid. Get
http://movementarian.org/oprofile-0.5.tar.gz, ./configure \
--with-kernel-support && make && make install

> --ctr0-event=CPU_CLK_UNHALTED && opcontrol --start

If it's an Intel CPU (not pentium 4) this should be OK
For Athlon, use INST_RETIRED

> do the trick? If that works does it mean oprofile is okay?

Run a few kernel compiles and stress it a bit. Run "op_time" to check
you get output...

> > I don't pretend to understand the PM layer at all, but it looks like
> > that both nmi.c's and oprofile's resume functions will get called. This
> > won't work: if oprofile has control of the perfctr's/nmi stuff, you
> > can't let the NMI watchdog's resume() be called, as it may conflict with
> > what oprofile is trying to resume.
> 
> oprofile() should already have checks to prevent that, and I added one

I haven't seen where you added these checks. They did not exist before:
oprofile took responsibility for the NMI/perfctr handling off the NMI
watchdog entirely, then handed it back when oprofile finished.

Basically you have to ensure that only the right pm callback is called,
not both.

> [        if (nmi_watchdog == NMI_LOCAL_APIC)

I don't see an added line like this ?

regards
john