On Tue, Jul 07, 2009 at 05:29:06PM -0700, Marcel Moolenaar wrote: > > On Jul 7, 2009, at 6:36 AM, Rink Springer wrote: > >> I tried to reproduce the error, got this on the way: > >> > >> # XXX: bogusly disabled high FP regs > > > > I get this message quite often as well; I intend to figure out what's > > going on. Marcel, if you have any idea, please let me know. > > It's a race condition. The high FP registers are lazily > context-switched and this error is emitted when a thread > wants to use the high FP registers when they are disabled > and the CPU onto which the thread is running has the high > FP registers corresponding to that thread in registers. > In that scenario the high FP registers should not even be > disabled. > > In the above case the kernel simply enables the high FP > registers and continues the thread. For the most part the > condition is harmless, but I've been looking at a panic > that's the result of inconsistency in the high FP state, > so the race is potentially fatal. > > BTW: I never got the error when doing a buildworld. I > think Anton's non-standard compiler options make GCC much > more FP intensive and thus prone to causing the race. Marcel, sorry, I probably misunderstood "compiler options" in the previous reply. Did you mean -j option in make -j10 buildworld? -- Anton Shterenlikht Room 2.6, Queen's Building Mech Eng Dept Bristol University University Walk, Bristol BS8 1TR, UK Tel: +44 (0)117 928 8233 Fax: +44 (0)117 929 4423Received on Wed Jul 08 2009 - 09:49:32 UTC
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