On Sun, 2008-09-14 at 21:51 +0200, Mike Galbraith wrote: > On Sun, 2008-09-14 at 09:18 -0500, Christoph Lameter wrote: > > Mike Galbraith wrote: > > > Numbers from my Q6600 Aldi supermarket box (hm, your box is from different shelf) > > > > > My box is an 8p with recent quad core processors. 8G, 32bit Linux. > > Don't hold your breath, but after putting my network config of a very > severe diet, I'm starting to see something resembling sensible results. Turns off all netfilter options except tables, etc. Since 2.6.22.19-cfs-v24.1 and 2.6.23.17-cfs-v24.1 schedulers are identical, and these are essentially identical with 2.6.24.7, what I read from numbers below is that cfs in 2.6.23 was somewhat less than wonderful for either netperf or tbench, Something happened somewhere other than the scheduler at 23->24 which cost us some performance, and another something happened at 26->27. I'll likely go looking again.. and likely regret it again ;-) Math ain't free is part of it, though apparently not much. For me, tbench regression 22->27 is ~10%, and netperf regression is ~16%. Data: 2.6.22.19 Throughput 1250.73 MB/sec 4 procs 1.00 16384 87380 1 1 60.01 111272.55 1.00 16384 87380 1 1 60.00 104689.58 16384 87380 1 1 60.00 110733.05 16384 87380 1 1 60.00 110748.88 2.6.22.19-cfs-v24.1 Throughput 1204.14 MB/sec 4 procs .962 16384 87380 1 1 60.01 101799.85 .929 16384 87380 1 1 60.01 101659.41 16384 87380 1 1 60.01 101628.78 16384 87380 1 1 60.01 101700.53 wakeup granularity = 0 (make scheduler as preempt happy as 2.6.22 is) Throughput 1213.21 MB/sec 4 procs .970 16384 87380 1 1 60.01 108569.27 .992 16384 87380 1 1 60.01 108541.04 16384 87380 1 1 60.00 108579.63 16384 87380 1 1 60.01 108519.09 2.6.23.17 Throughput 1192.49 MB/sec 4 procs .953 16384 87380 1 1 60.00 91124.67 .866 16384 87380 1 1 60.00 93124.38 16384 87380 1 1 60.01 92249.69 16384 87380 1 1 60.01 91103.12 wakeup granularity = 0 Throughput 1200.46 MB/sec 4 procs .959 16384 87380 1 1 60.01 95987.66 .866 16384 87380 1 1 60.01 92819.98 16384 87380 1 1 60.01 95454.00 16384 87380 1 1 60.01 94834.84 2.6.23.17-cfs-v24.1 Throughput 1242.47 MB/sec 4 procs .993 16384 87380 1 1 60.00 101728.34 .931 16384 87380 1 1 60.00 101930.23 16384 87380 1 1 60.00 101803.15 16384 87380 1 1 60.00 101908.29 wakeup granularity = 0 Throughput 1238.68 MB/sec 4 procs .990 16384 87380 1 1 60.01 105871.52 .969 16384 87380 1 1 60.01 105813.11 16384 87380 1 1 60.01 106106.31 16384 87380 1 1 60.01 106310.20 2.6.24.7 Throughput 1202.49 MB/sec 4 procs .961 16384 87380 1 1 60.00 94643.23 .868 16384 87380 1 1 60.00 94754.37 16384 87380 1 1 60.00 94909.77 16384 87380 1 1 60.00 95457.41 wakeup granularity = 0 Throughput 1204 MB/sec 4 procs .962 16384 87380 1 1 60.00 99599.27 .910 16384 87380 1 1 60.00 99439.95 16384 87380 1 1 60.00 99556.38 16384 87380 1 1 60.00 99500.45 2.6.25.17 Throughput 1220.47 MB/sec 4 procs .975 16384 87380 1 1 60.00 94641.06 .867 16384 87380 1 1 60.00 94864.87 16384 87380 1 1 60.01 95033.81 16384 87380 1 1 60.00 94863.49 wakeup granularity = 0 Throughput 1223.16 MB/sec 4 procs .977 16384 87380 1 1 60.00 101768.95 .930 16384 87380 1 1 60.00 101888.46 16384 87380 1 1 60.01 101608.21 16384 87380 1 1 60.01 101833.05 2.6.26.5 Throughput 1182.24 MB/sec 4 procs .945 16384 87380 1 1 60.00 93814.75 .854 16384 87380 1 1 60.00 94173.41 16384 87380 1 1 60.00 92925.24 16384 87380 1 1 60.00 93002.51 wakeup granularity = 0 Throughput 1183.47 MB/sec 4 procs .945 16384 87380 1 1 60.00 100837.12 .922 16384 87380 1 1 60.00 101230.12 16384 87380 1 1 60.00 100868.45 16384 87380 1 1 60.00 100491.41 2.6.27 Throughput 1088.17 MB/sec 4 procs .870 16384 87380 1 1 60.00 84225.59 .766 16384 87380 1 1 60.00 83362.65 16384 87380 1 1 60.00 84060.73 16384 87380 1 1 60.00 83462.72 wakeup granularity = 0 Throughput 1116.22 MB/sec 4 procs .892 16384 87380 1 1 60.00 92502.44 .841 16384 87380 1 1 60.01 92213.72 16384 87380 1 1 60.00 91445.86 16384 87380 1 1 60.00 91832.84 revert sched weight/asym changes, gran = 0 Throughput 1149.16 MB/sec 4 proc .918 16384 87380 1 1 60.00 94824.92 .868 16384 87380 1 1 60.01 94579.45 16384 87380 1 1 60.01 95284.94 16384 87380 1 1 60.01 95228.22 Weight/asym changes cost ~3%. Mysql+oltp agrees. Preempt happy loads lose a bit, preempt haters gain a bit. Performance shift. -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
