toolchain/57799: llvm amd64 builds are unbearbly slow and hit the build cluster time limit

[martin%NetBSD.org@localhost]

>Number:         57799
>Category:       toolchain
>Synopsis:       llvm amd64 builds are unbearbly slow and hit the build cluster time limit
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Dec 28 09:55:00 +0000 2023
>Originator:     Martin Husemann
>Release:        NetBSD 10.99.10
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD big-apple.aprisoft.de 10.99.10 NetBSD 10.99.10 (POWERMAC_G5.MP) #5: Fri Dec 15 21:02:28 CET 2023 martin%martins.aprisoft.de@localhost:/usr/src/sys/arch/macppc/compile/POWERMAC_G5.MP macppc
Architecture: powerpc
Machine: macppc
>Description:

Build for amd64 with llvm fail both on HEAD and netbsd-10 on the build cluster,
because they hit the 4h-per-single-arch-build time limit.

They are rund like this:

build.sh -m amd64 -B 202312241230Z -V NETBSD_OFFICIAL_RELEASE=no -D /home/builds/ab/HEAD-llvm/amd64/202312241230Z-dest -M /home/builds/ab/HEAD-llvm/amd64/202312241230Z-obj -R /home/builds/ab/HEAD-llvm/amd64/202312241230Z-rlse -T /home/builds/ab/HEAD-llvm/amd64/202312241230Z-tools -U -X /home/source/ab/HEAD-llvm/xsrc -x -N0 -V TMPDIR=/tmp -V BUILD=yes -V MKLLVM=yes -V HAVE_LLVM=yes -V MKGCC=no -V MAKECONF=/home/builds/etc/make.conf -V MKDEBUG=yes -j16 release iso-image install-image live-image


>How-To-Repeat:
s/a

>Fix:
n/a