4 ms·
"more accurate"? The rationale for (typically expensive) tracing in HPC circles is that sampling can miss things you want to pick up. I think that's also cove
by gnufx 4y ago
"more accurate"? The rationale for (typically expensive) tracing in HPC circles is that sampling can miss things you want to pick up. I think that's also covered in the vi-hps.org workshop introductions, for instance. (It doesn't necessarily involve recompilation.)
- mhh__ 4y ago"More accurate" is a condensed version of a longer (disclaimer-attached) statement about how I think they're more useful for typical profiling. If you want to know the exact ratios of how hot code is, then yes instrumentation can be a godsend, however in my experience most people are simply mislead by them because a naive instrumenting profiler usually does not have enough information to capture the right context (i.e. the call stack). For most applications profiling is basically just an exercise in proving your own mental model of execution correct, not fine-tuning (initially at least). https://youtu.be/6TDZa5LUBzY https://youtu.be/6TDZa5LUBzY I gave a talk on this in November.