On 11/09/2012 10:04 PM, Srivatsa S. Bhat wrote: > On 11/09/2012 09:43 PM, Dave Hansen wrote: >> On 11/09/2012 07:23 AM, Srivatsa S. Bhat wrote: >>> FWIW, kernbench is actually (and surprisingly) showing a slight performance >>> *improvement* with this patchset, over vanilla 3.7-rc3, as I mentioned in >>> my other email to Dave. >>> >>> https://lkml.org/lkml/2012/11/7/428 >>> >>> I don't think I can dismiss it as an experimental error, because I am seeing >>> those results consistently.. I'm trying to find out what's behind that. >> >> The only numbers in that link are in the date. :) Let's see the >> numbers, please. >> > > Sure :) The reason I didn't post the numbers very eagerly was that I didn't > want it to look ridiculous if it later turned out to be really an error in the > experiment ;) But since I have seen it happening consistently I think I can > post the numbers here with some non-zero confidence. > >> If you really have performance improvement to the memory allocator (or >> something else) here, then surely it can be pared out of your patches >> and merged quickly by itself. Those kinds of optimizations are hard to >> come by! >> > > :-) > > Anyway, here it goes: > > Test setup: > ---------- > x86 2-socket quad-core machine. (CONFIG_NUMA=n because I figured that my > patchset might not handle NUMA properly). Mem region size = 512 MB. >
For CONFIG_NUMA=y on the same machine, the difference between the 2 kernels was much lesser, but nevertheless, this patchset performed better. I wouldn't vouch that my patchset handles NUMA correctly, but here are the numbers from that run anyway (at least to show that I really found the results to be repeatable): Kernbench log for Vanilla 3.7-rc3 ================================= Kernel: 3.7.0-rc3-vanilla-numa-default Average Optimal load -j 32 Run (std deviation): Elapsed Time 589.058 (0.596171) User Time 7461.26 (1.69702) System Time 1072.03 (1.54704) Percent CPU 1448.2 (1.30384) Context Switches 2.14322e+06 (4042.97) Sleeps 1847230 (2614.96) Kernbench log for Vanilla 3.7-rc3 ================================= Kernel: 3.7.0-rc3-sorted-buddy-numa-default Average Optimal load -j 32 Run (std deviation): Elapsed Time 577.182 (0.713772) User Time 7315.43 (3.87226) System Time 1043 (1.12855) Percent CPU 1447.6 (2.19089) Context Switches 2117022 (3810.15) Sleeps 1.82966e+06 (4149.82) Regards, Srivatsa S. Bhat > Kernbench log for Vanilla 3.7-rc3 > ================================= > > Kernel: 3.7.0-rc3-vanilla-default > Average Optimal load -j 32 Run (std deviation): > Elapsed Time 650.742 (2.49774) > User Time 8213.08 (17.6347) > System Time 1273.91 (6.00643) > Percent CPU 1457.4 (3.64692) > Context Switches 2250203 (3846.61) > Sleeps 1.8781e+06 (5310.33) > > Kernbench log for this sorted-buddy patchset > ============================================ > > Kernel: 3.7.0-rc3-sorted-buddy-default > Average Optimal load -j 32 Run (std deviation): > Elapsed Time 591.696 (0.660969) > User Time 7511.97 (1.08313) > System Time 1062.99 (1.1109) > Percent CPU 1448.6 (1.94936) > Context Switches 2.1496e+06 (3507.12) > Sleeps 1.84305e+06 (3092.67) > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/