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OProfile is one of several profiling and performance monitoring tools for Linux. It works on various architectures, including the IA32, IA64, and AMD Athlon families, has a low overhead, and will be included in the 2.6 version of the kernel.

OProfile can help you identify issues such as loop unrolling, poor cache utilization, inefficient type conversion and redundant operations, branch mispredictions, and so on. It collects information about processor events including TLB misses, stalls, memory references, total lines allocated in the DCU (Data Cache Unit), the number of cycles of a DCU miss, and the number of non-cacheable and cacheable instruction fetches. OProfile is fine-grained and can collect samples for a set of instructions, or for function, system call, or interrupt handlers. OProfile works by sampling, and using the collected profile data, you can easily identify performance problems.

. . . See the entire article at developerWorks.