Re: RPi 4 build time
Date: Sun, 23 May 2021 02:05:56 UTC
On 2021-May-22, at 18:36, Mark Millard via freebsd-arm <freebsd-arm at freebsd.org> wrote: > On 2021-May-22, at 18:23, tech-lists <tech-lists at zyxst.net> wrote: > >> On Sat, May 22, 2021 at 04:51:31PM -0700, Mark Millard via freebsd-arm wrote: >> >>> In general these figures are approximations of the low >>> bound on a buildworld that is a (near) no-op but is >>> not frequently approached in my normal activity. But >>> it is rare for me to update the source tree again >>> and rebuild after only a few source commits after >>> what was originally rebuilt. For such, sub-half hour >>> rebuilds can certainly occur via META_MODE use. >>> >>> The context happened to be the ZFS based one in all >>> cases. Still no ccache use. >> >> That's wild. I have to look at meta mode. >> My use case though mostly involves building/updating ports with >> poudriere, and I'm happy it can use ccache. >> >> Am I right in thinking meta mode is a buildworld/kernel thing only? I've >> only heard of it; I know nothing about it. > > Yep: buildworld buildkernel only. > > META_MODE does not help for after a "rm -rf /usr/obj/*" > sort of clean-out. It just attempts to avoid rebuilding > materials already present that are sufficient. (It still > builds more than is strictly necessary: Some of the > dependency tracking tracks things that do not actually > imply needing a file rebuild. This is why installworld > to the live system ends up leading to a larger rebuild > later.) > I should have also mentioned the other side of META_MODE: It is there to also be sure to rebuild things that do need to be rebuilt. Its rebuilding more than necessary generally avoids ending up with insufficient/inaccurate rebuilds. Between ending up with false positives vs. false negatives, it has a definite bias. === Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)