Peter Maydell <peter.mayd...@linaro.org> writes: > On Mon, 5 Sept 2022 at 20:51, Claudio Fontana <cfont...@suse.de> wrote: >> when I build qemu, there is a lot of time spent at the end of the build >> where one cpu goes 100% on sphinx-build. >> >> Is there some way to parallelize that? It seems it is the current bottleneck >> for rebuilds for me.. > > It's a big fat python program, so I suspect not, but > maybe I'm wrong. > > You can always configure --disable-docs if you don't care > about the docs and want to make builds faster.
I care about the docs, but the impact on turnaround time is so bad I stopped building the docs in the build trees I use for development, and instead keep a separate tree that has docs enabled. Tends to delay diagnosis of doc markup errors, but that's the lesser evil for me. We used to have a similar problem with generated C: touch the QAPI schema, rebuild everything and its dog. That was because everything and its dog depended on the generated QAPI header. C projects 101: putting everything in a single header slows down rebuilds. We solved this by splitting up the generated header, and updating generated headers only when they actually change. I have no idea whether Sphinx could do a similarly incremental rebuild.
