Messages in this thread | | | Subject | Re: 2.6.27-rc4-git1: Reported regressions from 2.6.26 | From | Benjamin Herrenschmidt <> | Date | Mon, 25 Aug 2008 10:48:21 +1000 |
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> 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@bu3sch.de> > 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.
Ben.
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