2009/11/4 Ed Schouten <e...@80386.nl>: > Hi Attilio, > > * Attilio Rao <atti...@freebsd.org> wrote: >> Opteron rev E family of processor expose a bug where, in very rare >> ocassions, memory barriers semantic is not honoured by the hardware >> itself. As a result, some random breakage can happen in uninvestigable >> ways (for further explanation see at the content of the commit itself). > > Ooh. Sounds like an interesting bug. > > The bug doesn't manifest itself on UP, right? If so, maybe we should add > some very short instructions to the warning on how to disable SMP.
Due to the semantic of the bug, I think that it can manifest itself on UP and a memory barrier failing on UP means that PREEMPTION can blow up. Considering this I wouldn't suggest anything different between the UP vs SMP case. Attilio -- Peace can only be achieved by understanding - A. Einstein _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"