OProfile is a powerful system-wide profiler for Linux. Read
more at http://oprofile.sf.net

OProfile 0.8 has been released. OProfile is still in alpha,
but has been proven stable for many users.

New features
------------

Support for call-graph profiling on x86 2.6 kernels has been
implemented. You need to apply a kernel patch, available from

http://oprofile.sf.net/patches/

See the HTML documentation for details. Note this feature is still
experimental - feedback is welcome.

Unit mask is now a part of event specification meaning that you can
visualise profile with distinct event name, count and unit mask.

P4 HyperThreading support has been implemented for 2.4 kernels.

Pentium Mobile (P6 core) is supported when using kernel 2.6.3 and
upwards.

Support for ARM architectures has been added (timer interrupt is
supported in 2.6.3 and upwards; xscale support is in 2.6.6).

The --verbose option has been made more powerful.

Separate debug files (as used on Red Hat) are now supported.

When using 2.6 driver you can now set the per-cpu buffer size.

Improved statistics in oprofiled.log

It's no longer needed to be root to do an opcontrol --dump; this feature
requires a kernel patch not currently in mainline kernels.

Bug fixes
---------

With 2.6, the periodic flushing of the sample buffers (every 10 minutes)
was not working.

A build problem with the Intel compiler has been fixed (bug #845616).

When merging unit mask, the event description um part was incorrect.

When specifying invalid value to setup events like opcontrol -e
FOO:3000:0xx21 the unit mask was silently accepted with a zero value.

P4: Many unit-mask which were mandatory are set by default now, and
can't be modified. Many other small modifications in P4 unit mask
descriptions.

P4 with HyperThreading: the minimal event counts for all events has
been doubled to reduce risk of hangs.

With 2.4, 32 bit applications on AMD 64 can be profiled now (bug
#921243).

A small race with a modified binary file being profiled has been fixed.

Known problems
--------------

Over-writing binaries can cause oprofiled to abort (bug #931871).

On IA-64, some firmware revisions cause problems with OProfile (bug #931883).

The x86-64 port for 2.4 kernels seems to be broken (bug #840915).

Power management on laptops can be incompatible with OProfile in 2.4 (bug #554927).

Many Alpha ev67 events do not work (bug #931875).

A few Pentium IV events do not work (bug #841099).

The pre-emptable kernel option is not supported in 2.4 (bug #478516).

For 2.2 kernels, the module must be compiled as the same user
that owns the kernel source tree.
 
nosmp is not supported in kernels before 2.4.10 (bug #463087).