On Tue, 10 Jul 2007, Mathieu Desnoyers wrote: > cmpxchg_local is not available on all archs, but local_cmpxchg is. It > expects a local_t type which is nothing else than a long. When the local > atomic operation is not more efficient or not implemented on a given > architecture, asm-generic/local.h falls back on atomic_long_t. If you > want, you could work on the local_t type, which you could cast from a > long to a pointer when you need so, since their size are, AFAIK, always > the same (and some VM code even assume this is always the case).
It would be cleaner to have cmpxchg_local on all arches. The type conversion is hacky. If this is really working then we should also use the mechanism for other things like the vm statistics. > The measurements I get (in cycles): > > enable interrupts (STI) disable interrupts (CLI) local > CMPXCHG > IA32 (P4) 112 82 26 > x86_64 AMD64 125 102 19 Looks good and seems to indicate that we can at least double the speed of slab allocation. - 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/
