readme.md

Cycle-level Disaggregated Memory Simulator

Instructions to use cycle-level Disaggregated Memory Simulation Tool:

Simulation has to be started in two steps simultaneously:
- In the first step, instances (as per the number of nodes required to simulate) of pintool need to be started with the respective workloads to start production of instruction trace.
- In the second step, the simulator needs to be started to simulate the produced instructions traces of each node (one trace for each node).
- Instruction traces of multiple workloads can also be produced to represent traces for one-node (Multi-program support, not properly tested)

Instructions to compile Detailed Cycle-Level Simulation model:

The tool needs to set paths, either add pin-paths or copy this whole directory to the $pin-path/source/tools/detail/ (/detail is the new directory to be created)
Download DRACKSim2 from https://github.com/umd-memsys/DRAMSim2
Extract DRAMSim2 in this directory and name it as DRAMSim2
Apply DRAMSim2.patch on the extracted DRAMSim2 directory to apply all the modifications that we made on it and copy files from DRAMSIM2_ini/ to ini/ in DRAMSIM2:

patch -p1 < DRAMSim2.patch

go inside DRAMSim2 and build DRAMSim2 as a library:

cd DRAMSim2
make libdramsim.so
cd ..

Download and install the boost library in your system from https://www.boost.org/users/download/ or use the copy we provide in this repo.
Extract boost in the same directory
Set the number of nodes and remote memory pools in the mem_defs.cpp
Set the number of instructions or simulation cycles to simulate in the main.cpp
Create executable using 'make sim'

Instructions for producing instruction traces:

After copying this to $pin-path/source/tools/ use 'make pin' command to compile the instruction trace tool
Start as many instruction trace Pintools, as the number of nodes you set in the mem_defs.h (This is required, otherwise simulation will not start)
Samples for using the instruction trace tool are given in the 'bash start_sim.sh'
After every simulation, use 'bash clear_sm.sh', because the simulator creates shared memory variables and might create trouble during the next simulation if the execution was stopped in-between. clear_sm.sh will clear all the shared memory variables. Also kill the running workload (to be automated in next updates).

#Starting Simulation:

For simplification, you can either use multiple terminal windows or install 'screen' utility on your system
In first terminal, run 'bash start_sim.sh' to start production of instruction traces. You can specify different options while starting this tool.
- '- N x' : Mention the node number 'x' (mandatory argument)
- '-T 1/0' : '1' will only simulate multi-threaded part of the workload
- '-S n' : skip 'n' initial instructions
- '-S' and '-T' can be used together; skipping will be done in multi-threaded part if '-T 1' is used.
- '-M' : Number of instructions to trace and simulate (default 10M)
In the second terminal, start simulator DRackSim and pass the name of the output directory to it, e.g., ' ./DRackSim $OutDir numINST (10M default) '
The simulation will start and continue until the exit condition arrives.
The frequency of printing results can be changed using pre-processor #Result_cycle in main.cpp