Hello I am new to fast forwarding and I have been struggling with a problem for some days. I am trying to reduce the simulation time for my multiprocessor FS simulations and in order to do that I want to fast forward to a specific instruction count and execute in detailed mode from that point. Joel Hestness's example from the ISCA 2011 tutorial does not apply in my case since I do not want to switch in the beginning of my application but somewhere in the middle of it. I used the following command line:
./build/ALPHA_FS/m5.opt --trace-flags=myflag --trace-file=my_trace.out --outdir=stats/ configs/example/fs.py -n 2 --script=my_script.rcs --detailed --caches --l2cache --standard-switch -F 100967666 The fs.py script is the one distributed with M5 and I only modified some cache parameters (size etc.). To my understanding, the above command should start the simulation using AtomicSimpleCPU and after 100967666 instructions (this instruction count includes the boot and the initialization part of my application) should switch to detailed mode. However, the simulation takes way to much time (longer than it takes to run without the fast forward). M5's output is: M5 compiled Jun 22 2011 13:09:22 M5 revision e46d048f7e69+ 7074+ default tip M5 started Jun 22 2011 14:02:50 M5 executing on ubuntu command line:./build/ALPHA_FS/m5.opt --trace-flags=myflag --trace-file=my_trace.out --outdir=stats/ configs/example/fs.py -n 2 --script=my_script.rcs --detailed --caches --l2cache --standard-switch -F 100967666 Global frequency set at 1000000000000 ticks per second info: kernel located at: /home/vadmin/FullSystemImages/binaries/vmlinux Listening for system connection on port 3456 0: system.remote_gdb.listener: listening for remote gdb #0 on port 7000 0: system.remote_gdb.listener: listening for remote gdb #1 on port 7001 Switch at instruction count:100967666 info: Entering event queue @ 0. Starting simulation... warn: 337326000: Trying to launch CPU number 1! For more information see: http://www.m5sim.org/warn/8f7d2563 hack: be nice to actually delete the event here Switched CPUS @ cycle = 2338577694000 Changing memory mode to timing switching cpus Switch at instruction count:0 info: Entering event queue @ 2338577694000. Starting simulation... Switching CPUS @ cycle = 2340348678000 Simulation ends instruction count:0 info: Entering event queue @ 2340348678000. Starting simulation... switching cpus **** REAL SIMULATION **** info: Entering event queue @ 2340348679000. Starting simulation... warn: allocating bonus target for snoop For more information see: http://www.m5sim.org/warn/f15ea301 warn: allocating bonus target for snoop For more information see: http://www.m5sim.org/warn/f15ea301 warn: allocating bonus target for snoop For more information see: http://www.m5sim.org/warn/f15ea301 warn: allocating bonus target for snoop For more information see: http://www.m5sim.org/warn/f15ea301 warn: allocating bonus target for snoop For more information see: http://www.m5sim.org/warn/f15ea301 Am I doing something really stupid here? Can anyone provide me some insight into how to use fast forwarding or at least point me towards some documentation ( I already read http://www.m5sim.org/Sampling)? Thanks in advance! Alexandru _______________________________________________ gem5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
