Pahole: A Powerful Tool for Inspecting C/C++ Data Structure Memory Layouts

This blog post introduces pahole, a powerful tool for analyzing the memory layout of C/C++ data structures, including padding and alignment details. By reading the DWARF debugging information generated by the compiler, pahole visually displays how data structures are arranged in memory and points out "holes" inserted by the compiler to meet memory alignment requirements. This is crucial for optimizing code cache utilization and reducing cache line false sharing. The post also demonstrates how to install pahole and how to use its command-line options to analyze struct sizes, adjust member ordering to optimize memory layout, and explore memory layout differences under different cache line sizes.