Subject: Re: lint issues with larger caches
To: John Klos <john@ziaspace.com>
From: Riccardo Mottola <rollei@tiscalinet.it>
List: tech-toolchain
Date: 09/22/2005 10:09:19
Hello,

> Would anyone object to me committing the following change to
> src/usr.bin/xlint?
> 
> > # PowerPC processors with large and fast L2 caches (such as the
> > # 7447 and 7457) have problems with lint unless compiled with -O0.
> > .if ${MACHINE_ARCH} == "powerpc"
> > CPPFLAGS+=    -O0
> > .endif


I would be against this. It is not a real solution and you say yourself
"it happens with much less frequency".

Does your problem happen during a kernel build? I have a G4 with an
external L2 cache of 1Mb and I can build a kernel... if it doesn't crash
totally.

I keep top think that netbsd has a problem with caches... we had a
thread some weeks ago about problems I got when I upgraded to a g4/400
cache card with 1Mb of cache. Currently I have a quite stable kernel
since I put the cache in "WT" mode, which results in some performance
loss though. People on this list said that varting compilation
optimization levels of the kernel would make the problem go away. WHy I
verified that various -O level had a different degree of crash frequency
(up to not ebing able to complete a boot+login sometimes) it was just a
question on how much the computer was stressed and sooner or later it
would crash.

-R