On Wed, Jan 14, 2009 at 08:28:11PM +0100, Ingo Molnar wrote: > [v2.6.14] [v2.6.29] > > Semaphores | Mutexes > ---------------------------------------------- > | no-spin spin > | > [tmpfs] ops/sec: 50713 | 291038 392865 (+34.9%) > [ext3] ops/sec: 45214 | 283291 435674 (+53.7%) > > A 10x macro-performance improvement on ext3, compared to 2.6.14 :-) > > While lots of other details got changed meanwhile, i'm sure most of the > performance win on this particular VFS workload comes from mutexes. I asked a couple of our benchmarking teams to try -v9. Neither the OLTP benchmark, nor the kernel-perf test suite found any significant performance change. I suspect mutex contention isn't a significant problem for most workloads. Has anyone found a non-synthetic benchmark where this makes a significant difference? Aside from btrfs, I mean. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
