id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
3940	Serious performance degradation on the latest Linux nightly builds (+50% build time)	Francesco Casella	Martin Sjölund	"I have just re-run some tests on our power system models using the latest nightly {{{OpenModelica 1.10.0~dev-701-ga54c8a3}}}. The overall time to build the models has grown by about 50%(!!), spread among all compilation phases (front-end, back-end, simcode and templates).

I have talked to one of my co-workers, who's running experiments with the solar plant model, using the Linux nightlies. He also reports that using {{{OpenModelica 1.10.0~dev-665-gc82690e}}} (the nighly build of 25 May morning) he got a build time of about 400 seconds, while after updating to {{{1.10.0~dev-701-ga54c8a3}}} this morning, the build time has grown to 570 seconds, which is consistent with what I observed on the power system models. Unfortunately, I don't have any intermediate datapoints between those two nightlies.

I have double-checked the build time of the MSL coverage tests on Hudson between May 24 and May 30, but I cannot see this effect. On the contrary, the build time of the Engine V6 model went down from 45 seconds to 40 seconds between 26 May and 27 May and has stayed there since then.

So, I guess something went wrong with the build system, but honestly I couldn't say what it could be. Maybe some C compiler optimization gone astray? This could explain why all compilation phases are affected. Anyway, the loss of performance is quite severe.

Can you please have a look?"	defect	closed	blocker		Build Environment		worksforme		stetrab@…