* Matthew Wilcox <matthew@xxxxxx> wrote: > 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. basically only VFS is mutex-bound really, and few of the 'benchmarks' tend to be VFS intense. Maybe things like mail-server benchmarks would do that. Also, -v9 is like two days old code ;-) Old and crufty. The real performance uptick was not even in -v10 but in -v11 (the one we submitted in this thread). Ingo -- 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
