On Fri, Feb 15, 2002 at 03:11:18AM +0100, Ralf Baechle wrote:
> On Thu, Feb 14, 2002 at 05:56:31PM -0800, Jun Sun wrote:
> > I have been chasing a FPU register corruption problem on a SMP box. The
> > curruption seems to be caused by FPU emulator code. Is that code SMP safe?
> > If not, what are the volunerable spots?
> > Just thought I'd check before I dive into it ....
> In theory the fp emulation code should be MP safe as the full emulation
> is only accessing it's context in the fp register set of struct
> task_struct. The 32-bit kernel's fp register switching is entirely broken
> (read: close to non-existant). Lots of brownie points for somebody to
> backport that from the 64-bit kernel to the 32-bit kernel and forward
> port all the FPU emu bits to the 64-bit kernel ...
Brownie sounds good. :-) So what is the "fp register switching" you are
referring to? There is set of code related to lazy fpu context switch,
which seems to be working fine now.