TODO list at end of April
As April finished, useful to take stock of where analysis is at as well as next steps. During May, I may also take a few week break to finish publishing my book and a cycle trip- so also useful to … Continue reading →
Monthly Archives: April 2018
wspy – memory analysis for processes; need to sanity check the metrics…
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 →wspy – added –perfcounter-model application
I have added a new mode: –perfcounter-model application this supplements the previous two modes: –perfcounter-model process –perfcounter-model core This mode works similar to the process model, except only the root process is instrumented and then the “inherit” flag is passed. … Continue reading →
Adding robustness to building process trees
The ptrace(2) man page shows how one can subscribe for events such as PTRACE_EVENT_FORK or PTRACE_EVENT_VFORK type events that happens when a process calls fork()/vfork(). At such an event one can then call ptrace(PTRACE_GETEVENTMSG,…) to retrieve the pid of the … Continue reading →
wspy – added topdown memory analysis
As a followup to a previous post, I’ve added support to wspy for topdown analysis for backend stalls.
Continue reading →Investigating Intel performance counters for backend memory costing…
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 →
Off CPU analysis, getrusage, wait4 and related techniques…
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 →
wspy – process tracing, lost nodes and potential refactoring
One of the tough bugs I’ve noticed sometimes pop up is an “orphaned” process tree in my tree. When I’ve collected trees of processes, very occasionally I’ll have a tree node drop on the floor and show up as an … Continue reading →
Set up Ryzen 7 1700 system
I have set up a Ryzen 7 1700 system. I bought it at Costco at point it was discounted at point the older CPUs are getting discounted in time for newer.
Continue reading →Phoronix benchmarks – new Ryzen processors; looking @ the workloads
AMD released new Ryzen processors today. Phoronix published an article that benchmarked these processors. Anand Tech also published a review. TechReport also wrote a review. The posting is *not* measured on these new processors. Instead, it looks at dissecting the … Continue reading →