Hi John, I suggest using full system mode instead of SE mode if you're running a multithreaded workload. In FS mode, there's a full OS so it can handle thread switching, etc. For Parsec on x86 we've created a set of resources for you to get started. See https://gem5.googlesource.com/public/gem5-resources/+/refs/heads/stable/src/parsec/ for details.
Cheers, Jason On Fri, Apr 16, 2021 at 8:07 AM John Smith via gem5-users < gem5-users@gem5.org> wrote: > Hi All, > > I am sorry for the confusion. > > I am looking to run a multithreaded application on a mesh of 3x3 CPUs, > where the benchmark spawns 9 threads and each thread runs on > a single CPU (1:1). I went through the past discussions on this mailing > list and saw that m5threads was needed to do this. I have some questions. > > (1) If there are 9 CPU, and the host CPU launches 9 threads, then are 8 > threads launched on the remaining 8 CPUs and the 9th thread has to wait for > a > thread to complete to begin execution. If not then where does it run as > all the 9 CPUs are currently running a thread (1 host + 8 threads). > > (2) Anthony Gutierrez said that m5threads is no longer needed. Is that > correct for gem5-21 ? > (Subject: Simulating multiprogrammed & multithreaded workloads in SE > mode?) > > (3) Right now I am trying to build PARSEC 3.0 benchmarks with m5threads, > but I am receiving some errors as follows and I am not sure why: > > > > > > *base_dir/local/gcc/bin/gcc -O3 -g -funroll-loops -fprefetch-loop-arrays > base_dir/gem5dev/parsec-3.0/pkgs/pthread.o -static-libgcc > -Wl,--hash-style=both -Wl,--as-needed -DPARSEC_VERSION=3.0-beta-20150206 -o > siman_tsp siman_tsp.o -L base_dir/local/gcc/lib64 -L > base_dir/local/gcc/lib ./.libs/libgslsiman.a ../rng/.libs/libgslrng.a > ../ieee-utils/.libs/libgslieeeutils.a ../err/.libs/libgslerr.a > ../sys/.libs/libgslsys.a ../utils/.libs/libutils.a -lpthread > -lmbase_dir/gem5dev/parsec-3.0/pkgs/pthread.o: In function > `__pthread_initialize_minimal':pthread.c:(.text+0x97): undefined reference > to `_dl_phdr'pthread.c:(.text+0xd9): undefined reference to `_dl_phnum'* > > Generally how should I go about integrating the m5thread with any > benchmark? > > (4) Also, what other CPU benchmarks are recommended which are > multithreaded and can be run in a manner where I can > launch a thread on each CPU ? > > Thank You, > John Smith > > <https://www.mail-archive.com/search?l=gem5-users@gem5.org&q=from:%22Gutierrez%2C+Anthony%22> > > On Fri, Apr 16, 2021 at 1:50 AM Gabe Black via gem5-users < > gem5-users@gem5.org> wrote: > >> That's essentially right, although gem5 does have some plumbing to run >> multiple event queues within the same simulation which can coordinate with >> each other within a small window (quantum) of time. gem5 has support for >> fibers/threads/coroutines, but these are not typically used to model >> events. Events are processed inline when they happen using a simple >> function call. >> >> Gabe >> >> On Thu, Apr 15, 2021 at 2:46 AM gabriel.busnot--- via gem5-users < >> gem5-users@gem5.org> wrote: >> >>> Hi John, >>> >>> Short answer : no, you can only run several simulations in parallel, but >>> not a single simulation using one thread per CPU. >>> >>> Gem5 relies on Discrete Event Simulation (DES) to simulate the >>> concurrent behavior of HW. >>> DES is intrinsically sequential in its execution as it relies on >>> coroutines (also called user user threads, greed threads, fibers, etc.). >>> Parallelizing such application is a very hard task that often requires a >>> lot of subtle code transformations to efficiently protect shared resources. >>> If done correctly, then parallel DES does not have all the good >>> properties of classic DES, especially determinism... Unless you add extra >>> care to preserve it, which is hard, too. Trust me ;). >>> >>> This question has been discussed back in the days but seems stalled now: >>> http://www.m5sim.org/Parallel_M5 >>> >>> Cheers, >>> Gabriel >>> _______________________________________________ >>> gem5-users mailing list -- gem5-users@gem5.org >>> To unsubscribe send an email to gem5-users-le...@gem5.org >>> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s >>> >> _______________________________________________ >> gem5-users mailing list -- gem5-users@gem5.org >> To unsubscribe send an email to gem5-users-le...@gem5.org >> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s > > _______________________________________________ > gem5-users mailing list -- gem5-users@gem5.org > To unsubscribe send an email to gem5-users-le...@gem5.org > %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
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