Multiple CPUIDs not showing up in Gem5 simulation

Question

I am just starting out with gem5; I ran a program which was statically compiled using m5threads library, and ran using se.py with '-n 64' flag set. This should be simulating the program running on 64 cores [As per http://pages.cs.wisc.edu/~markhill/cs757/Spring2016/wiki/index.php?n=Main.Homework3], but the Exec traces only show operations from a single CPU. What am I doing wrong ?

Command line instruction ran:

Gem5/gem5/build/X86/gem5.opt --debug-flags=Exec,TLB,DRAM Gem5/gem5/configs/example/se.py -n 64 -c paper3/Blackscholes/blackscholes.out --options="1 paper3/Blackscholes/in_16.txt paper3/Blackscholes/output.txt"

score 0 · Answer 1 · answered Sep 24 '19 at 07:47

A similar thread happened recently at: https://www.mail-archive.com/gem5-users@gem5.org/msg16830.html

Some things you should check:

are you absolutely 100% certain that the content spawns threads? Ensure that by:
- reading its source code
- tracing with --debug-flags SyscallBase,SyscallVerbose and look for clone syscalls
m5threads is not needed anymore I believe. I'm sure this is the case for ARM at least
here is a minimal runnable example that spawns threads and does show multiple thread IDs on Exec trace and stats:
- https://github.com/cirosantilli/linux-kernel-module-cheat/blob/6aa375df2ad3ce2e7d741d09b378503c25547df1/userland/posix/pthread_self.c
- https://github.com/cirosantilli/linux-kernel-module-cheat/tree/e2b8bcdc3f6cc6803f3f89607bd118f812aed367#gem5-syscall-emulation-mode
don't forget that if the program will spawn 64 threads, then it likely uses 65 threads in total: main thread + 65, so maybe you will need 65 CPUs

../paper3/Sobel/sobeli1.pgm../paper3/Sobel/sobel: 0/l )64: version `GLIBC_2.7' not found (required by Is Gem5 asking for GLIBC_2.7 ? How can I incorporate that into Gem5 ? — Febin Sunny, Oct 04 '19 at 12:13
@FebinSunny If having that glbic version is crucial, compile or find a compiler built with that GLIBC. From source example at: https://stackoverflow.com/questions/10412684/how-to-compile-my-own-glibc-c-standard-library-from-source-and-use-it/52454710#52454710 Another possibility is to try with Buildroot. Otherwise, and that will be much easier, just compile everything from source with a recent ubuntu cross compiler. — Ciro Santilli, Oct 04 '19 at 13:19

Multiple CPUIDs not showing up in Gem5 simulation

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