Re: [Valgrind-users] DHAT speed

[Paul F. <pj...@wa...>]

> Message du 26/05/20 13:19> De : "John Reiser"  the ratio is about 1:50. So right away, that's a hardware slowdown of 4X.Maybe more. The machine has 12Mbyte of cache according to cpuinfo.> Valgrind runs every tool single-threaded. So if your app averages 5 active threads,> then that is a slowdown of 5X.I was running the application in single thread mode.> Valgrind's JIT (Just-In-Time) instruction emulator has a slowdown. Assume 10X (or measure nulgrind.)Yes, this is what I see with nulgrind, about a 11x factor slowdown. However this will also account for a large part of the cache overhead.> Finally we get to "useful work": the slowdown of the tool DHAT. Assume 3X.> So (4 * 5 * 10 * 3) is a slowdown of 600X, which turns 10 minutes into 100 hours.What I'm seeing is a DHAT-only slowdown that is much more than that.A+Paul