Optimizing existing large codebase Measuire Modemise Mem threads Finding bottlenecks Understand where we can improve o analyze each part of the software o in order to find out where most time is spent o and understand whether it can be improved Most usual bottlenecks From biggest to lowest impact(usually) 。10 ●Memory 。Parallelization o Low level behavior:vectorization,cache behavior,high CPl erf tool bottlenecks 12/62 S.Ponce-CERNOptimizing existing large codebase 12 / 62 S. Ponce - CERN Measure Modernize Mem threads low level c/c perf tools bottlenecks Finding bottlenecks Understand where we can improve analyze each part of the software in order to find out where most time is spent and understand whether it can be improved Most usual bottlenecks From biggest to lowest impact (usually) IO Memory Parallelization Low level behavior : vectorization, cache behavior, high CPI