Christoph Lameter <[EMAIL PROTECTED]> writes: > > Atomic operations may be enabled in the kernel configuration on > i386, ia64 and x86_64 if a suitable CPU is configured in SMP mode. > Generic atomic definitions for ptep_xchg and ptep_cmpxchg > have been provided based on the existing xchg() and cmpxchg() functions > that already work atomically on many platforms. It is very
I'm curious - do you have any micro benchmarks on i386 or x86-64 systems about the difference between spin_lock(ptl) access; spin_unlock(ptl); and cmpxchg ? cmpxchg can be quite slow, with bad luck it could be slower than the spinlocks. A P4 would be good to benchmark this because it seems to be the worst case. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
