Sorry, I misread your second question -- You should definitely run your algorithms through the simulator. The emulator does NOT model the coherency logic well.
Avadh got some speed up by running the multi-threaded version of MARSS: http://marssandbeyond.blogspot.com/2012/01/multi-threaded-simulation-in-marss.html I'm not sure the state of that branch, but it's worth a try if things are running too slowly for you. Tyler > There are some patches to qemu that have an effect even when running in > just plain emulation mode. MARSS leverages qemu to do some page table > book-keeping that I believe runs even when in pure emulation mode, for > example. If you're curious, you can grep for MARSS_QEMU in the qemu/ > directory to see such changes. That being said, these changes should not > have that much of an effect on qemu's performance when running in > emulation mode... have you tried running a stock qemu (without KVM, just > TCG?) > > Regarding lock-contention, the research community will absolutely accept > your work. MARSS models the coherency logic between CPUs very accurately > (and it's configurable). If you want to be especially crafty, you could > use the DRAMSim2 plugin to model the RAMs with high accuracy as well, but > you're probably more concerned with the coherency simulation (which is > provided by the default configuration). > > Tyler > >> Hi, >> >> I am trying to use MARSS for my research work on lock contention >> issues on parallel programs running on future many-core processors. >> When I tried to compile MARSS for 32 cores and run my parallel >> programs, I find it to take a lot of time. But when I just emulate >> (using the default QEMU available) instead of switching to simulation, >> obviously I could run my parallel programs faster and could simulate >> the lock contentions. I have few questions from these observations for >> which I look for clarifications: >> >> 1) When the MARSS is running in emulated mode is it just another QEMU? >> or is there any difference? >> 2) Since I am able to reproduce my lock contention problem using >> emulation(& the simulator being too slow for large core counts) I am >> thinking of working with it to test my algorithms. Will the research >> community accept the results obtained from an emulator? Kindly let me >> know. >> >> Thanks for your time, >> karthik >> >> _______________________________________________ >> 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
