ctracer made easy

Make sure you have the kernel-debuginfo package installed!

rpm -ivh http://oops.ghostprotocols.net:81/acme/dwarves/rpm/libdwarves1-0-9.i386.rpm http://oops.ghostprotocols.net:81/acme/dwarves/rpm/dwarves-0-9.i386.rpm
mkdir foo
cd foo
ln -s /usr/lib/ctracer/Makefile .
ln -s /usr/lib/ctracer/ctracer_jprobe.c .
make CLASS=sock
insmod ctracer.ko
# do some networking activity or just move the mouse 🙂
dmesg # or tail /var/log/messages
rmmod ctracer

Now to work on kahole, kill a hole, a tool that will reorganize structs to kill holes and that will provide the bits needed for struct “views”, i.e. to specify a list of fields in a struct that are of interest for collection at each probe point and that will also be used to create a userspace utility that will read the relay channel (/sys/kernel/ctracer0) and generate what ostra-cg, the callgraph tool from the OSTRA days needs to generate things such as this session collecting struct task_struct methods calls in the Linux kernel, ah, ostra-cg also produces this methods statistics and from this page you get plottings such as this one for sched_
fork calls, workload is forgotten right now, but as soon as I get my new test machine we’ll have more interesting graphics 🙂