src/sys/vm/vm_init.c v1.43 hangs amd64

[Doug White]

On Tue, 4 May 2004, David O'Brien wrote:

> On Sat, May 01, 2004 at 08:42:46AM -0700, Doug White wrote:
> > 2.  Changing COPTFLAGS to '-O -frename-registers -pipe' from the default
> > '-O2 -frename-registers -pipe' stops the crash. So it may be an
> > O2-specific optimization bug.
> ...
> > So in the end, at -O2, (nswbuf*MAXPHYS) != nswbuf*MAXPHYS. Creepy, eh?
> > I'll see if I can come up with a standalone test case to submit to the gcc
> > folks.
>
> Thanks!
> This is the first report of an -O2 problem, and I'm very happy you're
> willing to try to narrow this down so we don't have to return to -O[1].

I caught kan's attention with this last night on irc, and he's going to
try to isolate the bad code generation. We could really use a standalone
case to test with & submit, but a naieve test doesn't come up with any
differences.

In order to keep my amd64 stable I'm having to leave COPTFLAGS set, so if
someone commits a fix to gcc or imports a new version, try to get my
attention so I can test it with -O2 again.

Also if we get into the 5.3 release timeframe we'll have to make a call to
ship with a -O2 compiled kernel or not.

-- 
Doug White                    |  FreeBSD: The Power to Serve
dwhite at gumbysoft.com          |  www.FreeBSD.org