On Wed, Apr 25, 2018, at 12:32 PM, Jeff Muizelaar wrote: > At minimum we should make --enable-profiling build with rust-opt.
This sounds reasonable, although the quirk is that we default --enable-profiling on for nightly[1], so anyone building m-c will have it enabled. We could make the build system only do this for "explicitly enabled --enable-profiling", it just might be slightly confusing. (For reference, the rustc opt level is controlled here[2].) IIRC the slowdown from using opt-level=2 vs. 1 is primarily in LLVM? It would probably be useful if we instrumented the build to record compilation times for all of the crates we build at various optimization levels and see where the biggest issues are. Perhaps we could get someone on the Rust team to make some improvements if we know what the worst offenders are. -Ted 1. https://dxr.mozilla.org/mozilla-central/rev/26e53729a10976f52e75efa44e17b5e054969fec/js/moz.configure#243 2. https://dxr.mozilla.org/mozilla-central/rev/26e53729a10976f52e75efa44e17b5e054969fec/build/moz.configure/toolchain.configure#1397 _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
