OProfile is a system-wide profiler for Linux systems, capable of profiling
all running code at low overhead. OProfile is released under the GNU GPL.
For versions 0.9.7 and earlier, the profiler consists of a kernel driver
and a daemon for collecting sample data. In version 0.9.8, the kernel
driver/daemon method of collecting sample data is deprecated in favor of
profiling with the Linux Kernel Performance Events Subsystem (kernel version
2.6.31 or higher). Several post-profiling tools for turning profile data
into human readable information are available.
OProfile leverages the hardware performance counters of the CPU to enable
profiling of a wide variety of interesting statistics, which can also be
used for basic time-spent profiling. All code is profiled: hardware and
software interrupt handlers, kernel modules, the kernel, shared libraries,
OProfile is currently in alpha status; however it has proven stable over a
large number of differing configurations; it is being used on machines
ranging from laptops to 16-way NUMA-Q boxes. As always, there is no
- No special recompilations, wrapper libraries or the like are necessary.
Even debug symbols (-g option to gcc) are not necessary unless you want
to produce annotated source.
- Kernel patches are usually unnecessary, except in cases where the
running kernel may not yet support some newer processor models.
All code running on the system is profiled, enabling analysis of system
performance. Note: Root authority is required to do system-wide
Application developers will find the single-process profiling feature
very convenient since it does not require root authority, and profile
data is collected only for the specified process (or command). This
method has the added benefit of "following" fork/execs and collecting
profile information on those child processes as well. Note: This method
of profiling requires a kernel version of 2.6.31 or higher.
Performance counter support
Enables collection of various low-level data, and assocation with
particular sections of code.
With an x86 or ARM 2.6 kernel, OProfile can provide gprof-style
call-graph profiling data.
OProfile has a typical overhead of 1-8%, dependent on sampling
frequency and workload.
Profile data can be produced on the function-level or instruction-
level detail. Source trees annotated with profile information can be
created. A hit list of applications and functions that take the most
time across the whole system can be produced.
OProfile works across a range of CPUs, include the Intel range, AMD's
Athlon and AMD64 processors range, the Alpha, ARM, IBM PowerPC and
more. OProfile will work against almost any 2.2, 2.4 and 2.6 kernels,
and works on both UP and SMP systems from desktops to the scariest
NUMAQ boxes. Note: As of version 0.9.8, only 2.6 kernels are supported.
The early versions of OProfile were developed as part credit for an M.Sc. in
Computer Science. The basic principles of the design were inspired by Compaq's