I'm not entirely sure how interrupts are handled between QEMU and MARSS, but I wonder if this could be an artifact of a faster emulation speed causing interrupts to essentially move up in time. So if the hardware interrupts are moving out of the way faster on a faster host, the simulation is able to proceed quicker?
I could be completely off base here. On Wed, May 16, 2012 at 4:32 AM, Stefan Neumann < [email protected]> wrote: > Hi, > > I did a rerun of the benchmark with the latest MARSSx86 version > (code-cleanup branch) and the results are the same as for my previous run. > Still there are significant variations when running the benchmark on > machines with a different host frequency. > > Any guesses how to resolve this? > > Regards, > Stefan > > 2012/5/12 YaoQing,Wang <[email protected]> > > Hi Avadh >> >> Thanks for providing marssx86 simulator >> >> I have some question about this topic. >> The source code I checked out is from the "feature" branch with commit id >> a3aa5ad2db (committed on Feb 28,2012) >> >> Is this version free from this sim_cycle variation problem ? >> >> Thanks and Regards. >> >> Yao-Qing >> >> >> On Sat, May 12, 2012 at 12:07 AM, avadh patel <[email protected]>wrote: >> >>> >>> >>> On Fri, May 11, 2012 at 3:46 AM, Stefan Neumann < >>> [email protected]> wrote: >>> >>>> Sorry, the formatting got a little messed up. >>>> >>>> Host1: >>>> >>>> >>>> >>>> >>>> Host2: >>>> >>>> >>>> >>>> user uops >>>> kernel uops >>>> sim_cycle >>>> user uops >>>> kernel uops >>>> sim_cycle 7210746924 >>>> 1331578150 >>>> 13797811843 >>>> 7210744488 >>>> 1331141836 >>>> 13315031456 7210745232 >>>> 1331564187 >>>> 13767346806 >>>> 7210744417 >>>> 1331064636 >>>> 13343311719 7210744826 >>>> 1331475921 >>>> 13803067702 >>>> 7210745025 >>>> 1331429686 >>>> 13362192919 7210744068 >>>> 1331046761 >>>> 13778895729 >>>> 7210745138 >>>> 1331530721 >>>> 13371649704 7210743664 >>>> 1331602038 >>>> 13741170045 >>>> 7210746956 >>>> 1332519415 >>>> 13340211019 7210745221 >>>> 1331551159 >>>> 13765271526 >>>> 7210744700 >>>> 1332103942 >>>> 13357991805 7210747188 >>>> 1331712213 >>>> 13739122442 >>>> 7210744523 >>>> 1331264662 >>>> 13289832849 7210745019 >>>> 1331550151 >>>> 13758991929 >>>> 7210744052 >>>> 1331141885 >>>> 13791512144 >>>> >>>> >>>> This seems like an issue with VM's clock that was fixed in 0.3 release. >>> Which version are you using? Can you give the 'HEAD' commit id? >>> >>> - Avadh >>> >>> >>>> 2012/5/11 Stefan Neumann <[email protected]> >>>> >>>>> Hi, >>>>> >>>>> I am running some simulations of SPEC2006 benchmarks an noticed some >>>>> variations of the sim_cycle count when I run MARSS on different host >>>>> machines. >>>>> >>>>> Just an example: ROI of GemsFDTD >>>>> >>>>> I ran the simulation a couple of times on each host. >>>>> >>>>> Host1: Xeon X5670 @ 2.93GHz, dual socket, HT enabled >>>>> Host2: Xeon X5675 @ 3.07GHz, dual socket, HT enabled >>>>> OS configuration is exactly the same on both machines. >>>>> >>>>> Now when I compare the numbers: >>>>> >>>>> Host1: >>>>> >>>>> >>>>> Host2: >>>>> >>>>> user uops kernel uops sim_cycles >>>>> user uops kernel uops sim_cycles 7210746924 1331578150 13797811843 >>>>> 7210744488 1331141836 13315031456 7210745232 1331564187 13767346806 >>>>> 7210744417 1331064636 13343311719 7210744826 1331475921 13803067702 >>>>> 7210745025 1331429686 13362192919 7210744068 1331046761 13778895729 >>>>> 7210745138 1331530721 13371649704 7210743664 1331602038 13741170045 >>>>> 7210746956 1332519415 13340211019 7210745221 1331551159 13765271526 >>>>> 7210744700 1332103942 13357991805 7210747188 1331712213 13739122442 >>>>> 7210744523 1331264662 13289832849 7210745019 1331550151 13758991929 >>>>> 7210744052 1331141885 13791512144 >>>>> The number of simulated instructions is pretty stable for all runs, >>>>> but the sim_cycles, hence the IPC number differ. >>>>> Any idea what the reason for this might be, as it seems that those >>>>> differences more or less correlate with the clock rate of the host. >>>>> >>>>> Regards, >>>>> Stefan >>>>> >>>> >>>> >>>> _______________________________________________ >>>> http://www.marss86.org >>>> Marss86-Devel mailing list >>>> [email protected] >>>> https://www.cs.binghamton.edu/mailman/listinfo/marss86-devel >>>> >>>> >>> >>> _______________________________________________ >>> http://www.marss86.org >>> Marss86-Devel mailing list >>> [email protected] >>> https://www.cs.binghamton.edu/mailman/listinfo/marss86-devel >>> >>> >> > > _______________________________________________ > http://www.marss86.org > Marss86-Devel mailing list > [email protected] > https://www.cs.binghamton.edu/mailman/listinfo/marss86-devel > >
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