Re: LuaJit 1.1.0 coredump on FreeBSD

[Jim Mellander <jmellander@...>]

Hi Mike:

Thanks for your quick response.  It indeed looks like SSE is not enabled 
in the kernel per:

$ sysctl hw.instruction_sse
hw.instruction_sse: 0

However, this is a production kernel, for which any changes need to go 
thru a time-consuming QA process, as well as requiring me to run the 
gauntlet of fascist system administration :-(   Under the circumstances, 
I would prefer to take the performance hit by sinking back into the 
pre-SSE days.  I didn't see any option for disabling the use of SSE in 
the Luajit code - can this be done via a define?  Alternatively, is 
there some way to detect that although the CPU supports SSE, the kernel 
doesn't, and dynamically disable that code under the circumstances?


Thanks in advance.


Mike Pall wrote:
> Hi,
>
> Jim Mellander wrote:
>
> > I've been using Luajit 1.0.3 for my application with no problems on 
> > FreeBSD 4.10
> >
> > I built LuaJIT 1.1.0 ('make bsd') on the same system, and get the 
> > following problem:
> > [...]
> > Illegal instruction (core dumped)
>
>
> This looks like a problem with SSE2 code generation. It seems
> your kernel doesn't know how to deal with it even though your CPU
> supports it?
>
> I don't have access to a system with such an old version of
> FreeBSD. But a little research shows that SSE support must be
> explicitly enabled for 4.x with 'options CPU_ENABLE_SSE'. If your
> kernel doesn't have this, then you need to recompile it with this
> option.
>
> Bye,
>      Mike

--
Jim Mellander
Incident Response Manager
Computer Protection Program
Lawrence Berkeley National Laboratory
(510) 486-7204

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