[Cbe-oss-dev] GCC inline memcpy() from local store causes bad page fault

Andrew Pinski pinskia at gmail.com
Thu Mar 22 03:45:26 EST 2007

On 3/21/07, Segher Boessenkool <segher at kernel.crashing.org> wrote:
> For userland, we could fix all these by having the kernel
> emulate the insns.  Or compile the few affected userland
> apps/libs with the right compiler flags (which means adding
> a flag to disable lha/lwa generation).  Or both.  Which
> solution is preferred?

For the performance reasons, we should disable lha/lwa for the Cell as
they are microcoded.  But people don't always compile their code specifically
tuned for the Cell so you get some generic code which means they also should
be emulated in the kernel.

I think it would also be nice to be able to track when the alignment
exception is called
for user land, some kind of verbose output from exception handler so I
might be able to
better tune GCC.

Andrew Pinski

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