Even FS simulation should be deterministic. Although slight changes in inputs can have a significant effect if they cause changes in the order of locks etc., with *identical* inputs the simulation should produce *identical* results.
Steve On Wed, Sep 10, 2014 at 6:42 PM, biswabandan panda via gem5-users < gem5-users@gem5.org> wrote: > Non-determinism comes from the FS simulation. > You could try pinning the software threads to the > hardware threads. The miss rate varies because > of the dynamic behaviour of the synchronization primitives such as > barriers and locks. > > > On Wed, Sep 10, 2014 at 9:50 PM, Andreas Hansson via gem5-users < > gem5-users@gem5.org> wrote: > >> Hi Nizam, >> >> Could you elaborate on what is changing between the runs? >> >> The simulator is deterministic, so if everything stays the same you >> will get exactly the same output (otherwise we would never be able to run >> any regressions the way we do). >> >> Andreas >> >> From: Nizamudheen Ahmed via gem5-users <gem5-users@gem5.org> >> Reply-To: Nizamudheen Ahmed <nizam.ah...@gmail.com>, gem5 users mailing >> list <gem5-users@gem5.org> >> Date: Wednesday, 10 September 2014 16:50 >> To: gem5 users mailing list <gem5-users@gem5.org> >> Subject: [gem5-users] non-determinism in GEM5 stats >> >> Hi champs, >> >> I observe the stats.txt contain alarmingly different data across multiple >> run of the same benchmark under same target configuration. For example, i >> get 17% miss-rate and 5% miss-rate across two different runs. >> >> Can you help me identifying what could be going wrong? >> >> I have checkpointed the Linux boot and i am attempting to run PARSEC >> benchmark (blackscholes to be precise) ARM ISA. I also use m5::reset_stats >> and m5::dump_and_reset_stats around the ROI (i instrumented the hook.c in >> the PARSEC to invoke these calls). >> >> Thanks. >> >> Best regards, >> Nizam >> >> >> -- IMPORTANT NOTICE: The contents of this email and any attachments are >> confidential and may also be privileged. If you are not the intended >> recipient, please notify the sender immediately and do not disclose the >> contents to any other person, use it for any purpose, or store or copy the >> information in any medium. Thank you. >> >> ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, >> Registered in England & Wales, Company No: 2557590 >> ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, >> Registered in England & Wales, Company No: 2548782 >> >> _______________________________________________ >> gem5-users mailing list >> gem5-users@gem5.org >> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >> > > > > -- > > > *thanks®ards* > *BISWABANDAN* > http://www.cse.iitm.ac.in/~biswa/ > > “We might fall down, but we will never lay down. We might not be the best, > but we will beat the best! We might not be at the top, but we will rise.” > > > > _______________________________________________ > gem5-users mailing list > gem5-users@gem5.org > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >
_______________________________________________ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
