This page provides a number of patches to the 2.6 kernel driver you might find useful.
This patch provides a perfmon-based interface for OProfile. This allows the use of the IA-64's performance counters with OProfile. Note that many machines have a firmware bug that will lead to unusual behaviour; typically, samples stop arriving after a short period of idle time. A work-around for this firmware bug is disable the CONFIG_IA64_PAL_IDLE kernel option.
This patch provides support for call-graph profiling, currently only on x86. At each interrupt, the stack is recorded into the profile buffer, if the information is available in the registers. The user-space support for this, new in the 0.8 release, is still experimental.
Optimizations always bust things, because all optimizations are, in the long haul, a form of cheating, and cheaters eventually get caught.- Larry Wall