On Tue, 2022-06-14 at 13:11 -0400, Nick Bowler wrote: > The resulting config.h is correct but pa.sh took almost 1 minute to run > the configure script, about ten times longer than dash takes to run the > same script. More than half of that time appears to be spent just > loading the program into pa.sh, before a single shell command is > actually executed. Thanks for sharing that, it saves me looking into it! I work on a cross compiling build environment (Yocto Project) and we find that a large percentage of our build times (20%?) are in the configure stage, either running autoreconf or configure with a 50/50 split between the two. We autoreconf since we change the macros in some cases, e.g. libtool. I would love to find a way to be more efficient about this part of our builds. We do already provide some cached values for some macros to try and be a little more efficient. When I've profiled things, most of the time seems to be "fork" overhead of builds having to fork new processes to run shell command pipelines. I have sometimes wondered if we couldn't make code which was more optimised to the common case and didn't have so much forking going on. Cheers, Richard
