port-i386/57641: -current/i386 no longer installs in 32 MB

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         57641
>Category:       port-i386
>Synopsis:       -current/i386 no longer installs in 32 MB
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Oct 03 13:20:00 +0000 2023
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date >= 2023.09.23.18.21.43
>Organization:
>Environment:
System: NetBSD
Architecture: i386
Machine: i386
>Description:

In the ongoing discussion re "i386 minimum space requirements" on
port-i386, it was claimed that NetBSD/i386 will successfully install
with 32 MB of RAM.  I figured I'd test that in qemu using -current,
but it didn't work - sysinst hung at the point where it runs
"/usr/sbin/certctl rehash".

This appears to be a recent problem, even more recent than the
introduction of "/usr/sbin/certctl rehash" in sysinst.  A bisection
pointed at this commit:

  2023.09.23.18.21.11 ad src/common/lib/libc/gen/radixtree.c 1.32
  2023.09.23.18.21.11 ad src/sys/kern/init_main.c 1.546
  2023.09.23.18.21.11 ad src/sys/kern/kern_descrip.c 1.261
  2023.09.23.18.21.11 ad src/sys/kern/kern_lwp.c 1.255
  2023.09.23.18.21.11 ad src/sys/kern/kern_mutex_obj.c 1.14
  2023.09.23.18.21.11 ad src/sys/kern/kern_resource.c 1.194
  2023.09.23.18.21.11 ad src/sys/kern/kern_rwlock_obj.c 1.12
  2023.09.23.18.21.11 ad src/sys/kern/kern_turnstile.c 1.49
  2023.09.23.18.21.11 ad src/sys/kern/subr_kcpuset.c 1.20
  2023.09.23.18.21.11 ad src/sys/kern/vfs_cwd.c 1.11
  2023.09.23.18.21.11 ad src/sys/kern/vfs_init.c 1.64
  2023.09.23.18.21.11 ad src/sys/kern/vfs_lockf.c 1.81
  2023.09.23.18.21.11 ad src/sys/rump/librump/rumpkern/rump.c 1.360
  2023.09.23.18.21.12 ad src/sys/rump/librump/rumpvfs/rump_vfs.c 1.97
  2023.09.23.18.21.12 ad src/sys/sys/namei.src 1.64
  2023.09.23.18.21.12 ad src/sys/uvm/uvm_init.c 1.59
  2023.09.23.18.21.12 ad src/sys/uvm/uvm_map.c 1.410
  2023.09.23.18.21.12 ad src/sys/uvm/uvm_readahead.c 1.16
  2023.09.23.18.21.43 ad src/sys/rump/include/rump/rump_namei.h 1.52
  2023.09.23.18.21.43 ad src/sys/sys/namei.h 1.119

For logs, see:

  https://www.gson.org/netbsd/bugs/build/i386-lomem/commits-2023.09.html#2023.09.23.18.21.43

>How-To-Repeat:

  anita --sets base,kern-GENERIC,etc --memory-size 32M install http://nycdn.netbsd.org/pub/NetBSD-daily/HEAD/latest/i386/

>Fix: