On Thu, Jan 05, 2017 at 04:16:38PM +0800, Pan Xinhui wrote: > I do some tests about cmpxchg and cmpxchg_acquire before on ppc. > > loops in 15s of each cmpxchg is below. > > cmpxchg_relaxed: 336663 > cmpxchg_release: 369054 > cmpxchg_acquire: 363364 > cmpxchg: 179435 > > so cmpxchg is really expensive than others. > but I also have doubt about the cmpxchg_relaxed, it should be the cheapest, > but from the tests, release/acquire are faster than it.
Right, curious about that relaxed one. In any case, I was more wondering about the performance impact on the larger construct of the pvlock itself.
