Re: 2.6.27-rc4-git1: Reported regressions from 2.6.26

Rafael J. Wysocki
2008-08-25T11:40:43Z

On Monday, 25 of August 2008, Benjamin Herrenschmidt wrote:
>
> > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=11414
> > Subject : Random crashes with 2.6.27-rc3 on PPC
> > Submitter : Michael Buesch <mb-fseUSCV1ubazQB+pC5nmwQ@public.gmane.org>
> > Date : 2008-08-23 14:10 (1 days old)
> > References : http://marc.info/?l=linux-kernel&m=121950076812616&w=4
>
> This appears to be a gcc bug when -fno-omit-stack-pointer is used (which
> we mostly don't need on ppc anyway except that another gcc stupidity makes
> it mandatory for -pg which ftrace needs).
>
> We're working on a two fold workaround: removing -fno-omit-stack-pointer
> in all the cases where we don't really need it, and for when we do (ie,
> CONFIG_FTRACE becaues of -pg), using -mno-sched-epilog which seems to
> work around it.
>
> The root cause in gcc hasn't been fully identified yet.

Thanks Ben.

I've already dropped it from the list of recent regressions.

Rafael