Re: RPi 4 build time

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.)

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)