On Thu, Mar 09, 2017 at 07:45:13AM -0500, Ted Mielczarek wrote: > On Wed, Mar 8, 2017, at 05:43 PM, Ehsan Akhgari wrote: > > On 2017-03-08 11:31 AM, Simon Sapin wrote: > > > On 08/03/17 15:24, Ehsan Akhgari wrote: > > >> What we did in the Toronto office was walked to people who ran Linux on > > >> their desktop machines and installed the icecream server on their > > >> computer. I suggest you do the same in London. There is no need to > > >> wait for dedicated build machines. ;-) > > > > > > We’ve just started doing that in the Paris office. > > > > > > Just a few machines seem to be enough to get to the point of diminishing > > > returns. Does that sound right? > > > > I doubt it... At one point I personally managed to saturate 80 or so > > cores across a number of build slaves at the office here. (My personal > > setup has been broken so unfortunately I have been building like a > > turtle for a while now myself...) > > A quick check on my local objdir shows that we have ~1800 source files > that get compiled during the build: > $ find /build/debug-mozilla-central/ -name backend.mk -o -name > ipdlsrcs.mk -o -name webidlsrcs.mk | xargs grep CPPSRCS | grep -vF > 'CPPSRCS += $(UNIFIED_CPPSRCS)' | cut -f3- -d' ' | tr ' ' '\n' | wc -l > 1809 > > That's the count of actual files that will be passed to the C++ > compiler. The build system is very good at parallelizing the compile > tier nowadays, so you should be able to scale the compile tier up to > nearly that many cores. There's still some overhead in the non-compile > tiers, but if you are running `mach build binaries` it shouldn't matter.
Note that several files take more than 30s to build on their own, so a massively parallel build can't be faster than that + the time it takes to link libxul. IOW, don't expect to be able to go below 1 minute, even with 2000 cores. Mike _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
