Haai, Just to make a more-or-less general point (or two)...
"Otto Moerbeek" <o...@drijf.net> wrote: > On Fri, Mar 27, 2020 at 09:03:40PM +0000, Stefmorino wrote: > >> I have tested many applications, the behavior is the same in all of them, but >> I'll talk about OpenMW (an open-source game engine for morrowind) since I >> have >> the most useful information about how this program is threaded. By default, >> OpenMW uses 4 threads (cited here: >> https://openmw.readthedocs.io/en/stable/reference/modding/settings/cells.html), >> one for main/generic processing, one for graphics, one for audio, and one for >> preloading terrain. >>[snip] >> >> Is it a lock (spin is at 0)? A placeholder? A limitation of how Ryzen SMP is >> implemented? >[snip] > > Wild guess: it could be that you program actually does not do real > threading, but userland threading. "Fibering", in other words. > Check with top -H if it really > creates threads. You should see multiple threads having the same PID. > or all thraeds are using a resource that cannot be shared. Likely the latter. It's always funny, isn't it... A coder thinks "hey, I want a multi-threading 'cause its 1337, I'll just neatly run these subsystems within seperate threads and I'm done!". The fact that such is a frequently a naive proposition should be clear to the more clueful reader. Games tend to be heavy on global state, and are more likely to benefit from a multi-process model w/ carefully thought-out boundaries, than from a shared-everything thread model. While that need not be the case here, mestrongly suspects it is. Take heed, and measure. Always measure. Take care, --zeurkous. > -Otto -- Friggin' Machines!
