I have updated the topdown wrapper script to add some additional cache statistics for level 3 backend related information. I have also added a -x option to display some rusage information.
Continue reading →The Intel topdown performance analysis method separates out frontend stalls (level 1) into latency (level 2) and bandwidth (level 2). A frontend latency stall is when 0 uops are issued at all because the frontend is waiting. A frontend bandwidth … Continue reading →
I have added a basic tool “topdown” that is a wrapper to collect topdown metrics.
Continue reading →After my previous post on backend analysis, I got a chance to look further breaking out backend stall statistics.
Continue reading →As a followup to this post, I’ve implemented per-process capture of backend counters. I can now create a memory report from a process tree.
Continue reading →I’ve implemented the first level for topdown performance counter analysis and also done an initial analysis of ~15 workloads from recent Phoronix article. A logical next step is to expand the “backend bound” category to first separate CPU-bound vs. memory-bound … Continue reading →
As I looked to analyze x264, I saw that the On CPU metric was considerably less than other benchmarks like openssl or c-ray that are On CPU almost 100% of the time. I also noticed that my Ryzen 1700 box … Continue reading →
I have updated wspy to dump a “processtable.csv” file at the same time it dumps a “processtable.txt” file. This gives me several advantages: I’ve separated the format of output from collecting instrumentation. Hence, I can run things once to collect … Continue reading →
This article summarizes three overall metrics to assess performance of a workload running on a microprocessor. These metrics provide an overall picture of what determines the performance and provide clues on where to dig for a deeper understanding. Following the … Continue reading →