Memprof Kernel Module

The Memprof Kernel Module collects IBS samples and sets up hooks in the perf event subsystem.

WARNING

This module only works on AMD processors. Intel processors are not yet supported by Memprof.

How to compile

This kernel module overloads some kernel functions that are not directly exported to modules. In order to do that, the module looks for symbols in /boot/System.map-your-kernel-version.

Most distributions are shipped with a System.map file. If you do not have a System.map file, you can obtain one by downloading a new kernel and compiling it as follows:

make -j64

KN="vmlinuz"
KV=`make kernelversion`
sudo make modules_install;
sudo cp arch/x86/boot/bzImage /boot/${KN}-${KV}
sudo cp System.map /boot/System.map-${KV}
sudo cp .config /boot/config-${KV}
sudo mkinitramfs -o /boot/initrd.img-${KV} ${KV}

WARNING: this module has only been tested on kernels 3.6 to 3.8.

Usage

(To get the libraries, the parser and the scripts referenced in the following code, see https://github.com/Memprof.)

../scripts/profile_app.sh <app>

or 

sudo insmod ./memprof.ko 
rm /tmp/data.*
echo b > /proc/memprof_cntl 
LD_PRELOAD=../library/ldlib.so <app> 
echo e > /proc/memprof_cntl 
cat /proc/memprof_ibs > ibs.raw 
cat /proc/memprof_perf > perf.raw 
../library/merge /tmp/data.* 
../parser/parse ibs.raw --data data.processed.raw --perf perf.raw [options, e.g. -M] 

Notes

To set sampling frequency change the mod-memprof.c code: int max_cnt_op = your-value;

Reference

Memprof is described in the following paper "MemProf: A Memory Profiler for NUMA Multicore Systems".