LTTng-profile modules

Kernel module for LTTng-profile.

Sends a signal to applications profiled with the LTTng-profile userspace libray when they spend more than a predefined amount of time in a system call.

Building

You will need to have your kernel headers available (or access to your full kernel source tree), and do:

make
sudo make modules_install
sudo depmod -a

The above commands will build the modules against your current kernel. If you need to build the modules against a custom kernel, do:

make KERNELDIR=/path/to/custom/kernel
sudo make KERNELDIR=/path/to/custom/kernel modules_install
sudo depmod -a kernel_version

Required kernel config options

Make sure your target kernel has the following config options enabled:

• CONFIG_MODULES: loadable module support
• CONFIG_KALLSYMS: see files in wrapper; this is necessary until the few required missing symbols are exported to GPL modules from mainline

Usage

To load the module:

sudo ./load

Once the module is loaded, an ioctl() API on /proc/lttngprofile file becomes available.