valgrind is great, but be aware that valgrind runs single-threaded, which definitely changes the way multi-threaded apps behave: https://valgrind.org/docs/manua

valgrind is great, but be aware that valgrind runs single-threaded, which definitely changes the way multi-threaded apps behave: https://valgrind.org/docs/manual/manual-core.html#manual-core.pthreads_perf_sched https://valgrind.org/docs/manual/manual-core.html#manual-cor... In practice what this means is that cpu-bound threads can monopolize the single thread, and we've had thread starvation issues as a result in some tests. Setting the "-fair-sched" option resolved those issues, but made valgrind run even slower ...