On Mon, Jul 08, 2002 at 10:21:56AM -0700, Jun Sun wrote: > > No, Sony's ABI isn't MP proof and will break silently on MP systems. As > > such I can't consider it anything else but a hack. sysmips(MIPS_ATOMIC_SET, > > ...) and ll/sc however are MP proof. > > > > > sysmips(MIPS_ATOMIC_SET, ...) as it is is not MP-safe. Two processors can > set the variable at the same time since no spinlock is used to protect the > access. Note there are two cases in the code, one using ll/sc which is MP proof and a second implementation for machines that don't have these instructions. At least for now Linux/MIPS SMP systems by definition have ll/sc, so I don't see any problem. > This is also a problem when I was writing preemptiable kernel patch. Thanks for the reminder. I'm just working on the merge with 2.5.4 which has all the preemption stuff. Another one for the to-do list ... Ralf
