Re: [PATCH v2] pseries: don't override CONFIG_PPC_PSERIES_DEBUG

From: Michael Ellerman
Date: Fri Oct 15 2010 - 00:01:53 EST


On Thu, 2010-10-14 at 20:54 -0500, Linas Vepstas wrote:
> On 14 October 2010 19:48, Nishanth Aravamudan <nacc@xxxxxxxxxx> wrote:
> > eeh and pci_dlpar #undef DEBUG, but I think they were added before the
> > ability to control this from Kconfig. It's really annoying to only get
> > some of the debug messages from these files. Leave the lpar.c #undef
> > alone as it produces so much output as to make the kernel unusable.
> > Update the Kconfig text to indicate this particular quirk :)
> >
> > Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxx>
>
> OK, ignore my last email.
>
> Acked by: Linas Vepstas <linasvepstas@xxxxxxxxx>

I guess I'll ack it too seeing I added PPC_PSERIES_DEBUG:

Acked-by: Michael Ellerman <michael@xxxxxxxxxxxxxx>

> > --- a/arch/powerpc/platforms/pseries/Kconfig
> > +++ b/arch/powerpc/platforms/pseries/Kconfig
> > @@ -47,6 +47,12 @@ config LPARCFG
> > config PPC_PSERIES_DEBUG
> > depends on PPC_PSERIES && PPC_EARLY_DEBUG
> > bool "Enable extra debug logging in platforms/pseries"
> > + help
> > + Say Y here if you want the pseries core to produce a bunch of
> > + debug messages to the system log. Select this if you are having a
> > + problem with the pseries core and want to see more of what is
> > + going on. This does not enable debugging in lpar.c, which must
> > + be manually done due to its verbosity.
> > default y
>
> Umm, I see "default y" and you are not changing this but ... default y
> ?? Really?

Yes, default y if early debug is enabled. Unlike DEBUG_KERNEL,
PPC_EARLY_DEBUG is a pretty good indication that you are doing some
kernel development - because you have to choose exactly which platform
you're working on.

> Also, I am guessing that the lpar spam is due only to a handful of printk's,
> while most of the rest will be infrequent. Just knock out the
> high-frequency ones...

No they're all related to the HPTE code, so you basically don't want any
of them enabled unless you're debugging that, and most people aren't.

cheers

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