On Wednesday, 29 November 2023 12:06:15 GMT Peter Humphreey wrote: > On Wednesday, 29 November 2023 10:26:36 GMT Michael wrote: > > Here's my hypothesis explaining your own observation with libreoffice. As > > a package or more finished emerging, libreoffice's turn comes up. Soon > > libreoffice starts to execute make jobs, but any of the following may > > apply: > > > > 1. There are only 4 out of 30 jobs available, because other packages are > > already using 26, throughout your window of observation. > > Nope. Nothing else in progress. > > > 2. Libreoffice sequencing of make jobs is mostly linear with succeeding > > make jobs waiting on output from their predecessors. > > That's possible, but it doesn't seem likely with such a huge code base. And > why four processes, specifically and consistently? > > > 3. Libreoffice source code is not optimised for high parallelism - I > > recall > > when it was hardcoded at -j1 just a few years ago. Before this > > restriction > > was added, any bug reporters were advised to try again after limiting make > > to -j1. > > Yes, that was common to many packages for a long time because of incomplete > optimisation. > > > Next time I'm building libreoffice on a beefier system I'll keep an eye > > out > > for the number of jobs to see what it gets up to. > > That would help, yes.
OK, I eventually got around to it. I am observing right now LO is building with as many as 24 jobs: top - 11:14:59 up 2:19, 2 users, load average: 24.46, 23.15, 9.51 Tasks: 474 total, 25 running, 449 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.2 us, 5.6 sy, 94.0 ni, 0.2 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st MiB Mem : 64217.1 total, 50028.6 free, 6233.7 used, 7954.9 buff/cache MiB Swap: 0.0 total, 0.0 free, 0.0 used. 54333.4 avail Mem I don't use distcc. The make -j25 -l24.8 I have specified is respected. > The contribution of distcc isn't clear to me yet, as I said before. > Sometimes it's the bee's knees; other times it might just as well not be > there. I don't like mysteries... :)
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