On sábado, 26 de novembro de 2016 13:01:03 PST Ch'Gans wrote: > On 26 November 2016 at 11:57, Thiago Macieira <thiago.macie...@intel.com> wrote: > > That's a useless result. Your tool is telling you not the proper time of > > each function, but the aggregate time of that function and everything it > > called. > Well, I thought that maybe the role of _dl_runtime_resolv_avx was to > actually only resolve the function, not execute it as well...
Yes, and after resolving that function, it calls that function. > > It's like saying that your application spends most of its time in main. We > > knew that... Drill down and find out what's happening. Very likely, the > > effect you turned on is too slow for your CPU or GPU, or in combination > > with some other system-dependent use. > > /proc/cpu tells me that the CPU supports AVX (no trace of AVX2). So > could it be a bug somewhere. basically the wrong implementation is > called, or my CPU is not good enough, well it's a modern AMD: "AMD > FX(tm)-8320 Eight-Core Processor". That explains why _dl_runtime_resolve_avx was used, as opposed to the non-AVX version of it. Note that I can't find that function in glibc's source code. If it really is a problem, then your distribution caused it by applying a patch and you should complain to them. But I don't think that this the problem. Stop looking at _dl_runtime_resolve_avx, that's a red herring. Your problem is elsewhere. > What I'm trying to find out, is that is it a Qt problem (relying on > AVX2 on a CPU that doesn't support it), or is it a KUbuntu problem, or > ... I'll take the "..." as the problem. > As well, is there a simple way to disable AVX2 within Qt? Yes. But it's already disabled. And that's not the problem. > I find it a bit crazy that Qt graphics performance are that bad on a > modern desktop computer using latest (or almost) AMD CPU. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
