G 3 <programmingk...@gmail.com> writes: > On Aug 12, 2016, at 9:19 AM, Alex Bennée wrote: > >> On 11 August 2016 at 17:43, G 3 <programmingk...@gmail.com> wrote: >>> >>> On Aug 11, 2016, at 11:24 AM, qemu-devel-requ...@nongnu.org wrote: >>> >>> >>> Performance >>> >>> =========== >>> >>> >>> You can't do full work-load testing on this tree due to the lack of >>> >>> atomic support (but I will run some numbers on >>> >>> mttcg/base-patches-v4-with-cmpxchg-atomics-v2). However you certainly >>> >>> see a run time improvement with the kvm-unit-tests TCG group. >>> >>> >>> retry.py called with ['./run_tests.sh', '-t', '-g', 'tcg', '-o', >>> '-accel >>> tcg,thread=single'] >>> >>> run 1: ret=0 (PASS), time=1047.147924 (1/1) >>> >>> run 2: ret=0 (PASS), time=1071.921204 (2/2) >>> >>> run 3: ret=0 (PASS), time=1048.141600 (3/3) >>> >>> Results summary: >>> >>> 0: 3 times (100.00%), avg time 1055.737 (196.70 varience/14.02 >>> deviation) >>> >>> Ran command 3 times, 3 passes >>> >>> retry.py called with ['./run_tests.sh', '-t', '-g', 'tcg', '-o', >>> '-accel >>> tcg,thread=multi'] >>> >>> run 1: ret=0 (PASS), time=303.074210 (1/1) >>> >>> run 2: ret=0 (PASS), time=304.574991 (2/2) >>> >>> run 3: ret=0 (PASS), time=303.327408 (3/3) >>> >>> Results summary: >>> >>> 0: 3 times (100.00%), avg time 303.659 (0.65 varience/0.80 >>> deviation) >>> >>> Ran command 3 times, 3 passes >>> >>> >>> The TCG tests run with -smp 4 on my system. While the TCG tests are >>> >>> purely CPU bound they do exercise the hot and cold paths of TCG >>> >>> execution (especially when triggering SMC detection). However >>> there is >>> >>> still a benefit even with a 50% overhead compared to the ideal 263 >>> >>> second elapsed time. >>> >>> >>> Alex >>> >>> >>> >>> Your tests results look very promising. It looks like you saw a 3x >>> speed >>> improvement over single threading. Excellent. I wonder what the >>> numbers >>> would be for a 22 core Xeon or 72 core Xeon Phi... >> >> Well the initial results look like they tail off but I need to test >> on a more >> capable machine. I'm going to package up the test case first so people >> can easily >> replicate the test. >> >>> Do you think you could some test with an x86 guest like Windows >>> XP? There >>> are plenty of benchmark tests for this platform. Video encoding, >>> Youtube >>> video playback, and number crunching programs' results would be very >>> interesting to see. >> >> I don't have any Windows images to hand I'm afraid. Besides Windows >> is a fairly >> boring guest from this point of view because: >> >> - it's x86, so why use TCG over KVM >> - QEMU TCG generally sucks at media bencmarks due to SIMD emulation > > Mac OS X host don't have a hypervisor that QEMU supports (VirtualBox > isn't supported), so TCG is the only thing that can be used. Maybe a > free x86 guest like Linux could be used?
Sounds like you have the kit for this test case. Let me know if the branch boots your test images? -- Alex Bennée
