On Tue, 30 Oct 2007, Andrew Morton wrote: > Let's cc linux-arch: presumably other architectures can implement cpu-local > cmpxchg and would see some benefit from doing so.
Matheiu had a whole series of cmpxchg_local patches. Ccing him too. I think he has some numbers for other architectures. > The semantics are "atomic wrt interrutps on this cpu, not atomic wrt other > cpus", yes? Right. > Do you have a feel for how useful it would be for arch maintainers to > implement > this? IOW, is it worth their time? That depends on the efficiency of a cmpxchg_local vs. the interrupt enable/ disable sequence on a particular arch. On x86 this yields about 50% so it doubles the speed of the fastpath. On other architectures the cmpxchg is so slow that it is not worth it (ia64 f.e.) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
