On Thu, Mar 22, 2018 at 08:56:36 +0000, Alex Bennée wrote: > > Emilio G. Cota <c...@braap.org> writes: > > <snip> > > For performance numbers see the last patch. > > Just another random data point as we've been using himeno for our SVE > wor: > > Master: > > 8:05:45 [alex@zen:~/l/q/qemu.git] master ± ./aarch64-linux-user/qemu-aarch64 > sve.demo/himeno-v80 > mimax = 129 mjmax = 65 mkmax = 65 > imax = 128 jmax = 64 kmax =64 > cpu : 33.430299 sec. > Loop executed for 200 times > Gosa : 1.688752e-03 > MFLOPS measured : 98.519585 > Score based on MMX Pentium 200MHz : 3.052978 > > Host FPU: > > 08:25:03 [alex@zen:~/l/q/qemu.git] master ± ./aarch64-linux-user/qemu-aarch64 > sve.demo/himeno-v80 > mimax = 129 mjmax = 65 mkmax = 65 > imax = 128 jmax = 64 kmax =64 > cpu : 15.067773 sec. > Loop executed for 200 times > Gosa : 1.688752e-03 > MFLOPS measured : 218.581684 > Score based on MMX Pentium 200MHz : 6.773526 > > Given SVE also beats v80 code thanks to avoiding marshalling overhead by > doing bigger vectors I expect that improvement to be even better. Once > the SVE patches are re-based I'll measure them.
This is nice to see. It is possible though that this code uses other FP instructions that this patchset doesn't speed up; perf record/report will point to those, if any. > By the way I've been talking to some of the people at connect about > tracking performance over time. I got pointed to LLVM's LNT tool > (example: https://lnt.llvm.org/) so I might see if I can get a server > set up that we can start pushing numbers to. Have you come across any > other such things? I like the idea of having a server to test for performance regressions. Perhaps the hardest bit would be to choose what benchmarks to run. We could start with nbench and (parallel w/ MTTCG) bootup+shutdown tests, although having access to SPEC (it's proprietary) would be nice; as you can see below I think SPEC has a better job than nbench at characterizing performance. I have scripts for automatically generating perf numbers and plots; I could share those. With them, generating plots like the following is trivial (if you discount the time it takes for the tests to run, heh): https://imgur.com/a/5P5zj context: http://lists.gnu.org/archive/html/qemu-devel/2018-03/msg01206.html Thanks, Emilio
