On 19-Dec-00 Maciej W. Rozycki wrote: > On Mon, 18 Dec 2000, Jun Sun wrote: >> What do we offer to machines without ll/sc? > > I asked Ralf for a clarification of the sysmips(MIPS_ATOMIC_SET, ...) > call before I write better code. No response so far. I'm now really > cosidering implementing the Ultrix atomic_op() syscall -- at least it has > a well-known defined behaviour. Another possibility would be to rely on the userland ll/sc emulation in the kernel. The one in the linux-vr tree seems to be working well and can easily be backported to Linux/MIPS. Advantage: userland binary compatibility. Disadvantage: possibility for a lot of context switches for userland atomic operations. Having a sysmips(MIPS_ATOMIC_SET, ...) or atomic_op() solution would probably a lot faster. Maybe we should implement both :) -- Regards, Harald
