Silent hang in buildworld, was Re: Invoking -v for clang during buildworld

[Mark Millard]

> . . .
> FYI: I re-established my access to a RPi2B V1.1 and made
> it report: "maximum recommended amount (468832 pages)"
> 
> (The figure can vary some from release to release.)
> 
> 468832*4096 == 1920335872 or a little over 1831 MiBytes
> 
> For the 4096 Byte pages, that means that the following from
> gpart fits without complaint (size is in blocks, not pages):
> 
>  413140992    3686400  da0p2  freebsd-swap  (1.8G)
> 
> 3686400*512 is a little over 1.75 GiByte or 1800 MiByte. So
> I've left some room below 1831 MiBytes, but not a lot.
> 
> FYI about my build experiment that is running:
> 
> # sysctl hw.physmem
> hw.physmem: 979042304
> 
> which, in recent times for armv7, I can (and did) set in
> /boot/loader.conf on a faster cortex-A7 SBC (that can boot
> the same media but has more RAM).
> 
> So I tried a -j4 build, but with LDFLAGS.lld+= -Wl,--threads=1
> in use and my other particular src.conf/make.conf like content
> (so the builds do likely differ from yours in various ways).
> My build is producing a non-debug build (but with -g symbols).
> Somewhat after where your buildworld.log stops, my odd variant
> of top was reporting:
> 
> Mem:  . . . , 753672Ki MaxObsActive, 200412Ki MaxObsWired, 892732Ki MaxObs(Act+Wir)
> Swap: . . . , 145832Ki MaxObsUsed
> 
> and top was also showing lots of processes as having "0B" RES
> in STATE "wait" or "nanslp" (so, apparently swapped out, not paging).
> ("MaxObs" is short for "maximum observed".)
> 
> For comparison, your swapscript.log reported a maximum total of
> 346192 KiBytes "Used" for swap, about 98% into the log file.
> 
> (Time goes by . . .)
> 
> It finished with building libllvm and is part way into building
> libclang. This is probably well past where your hangup happened,
> given that your published buildworldlog file stopped with
> libllvm's Target/ARM/ARMMCInstLower.o . My odd top now shows:
> 
> Mem:  . . . , 753672Ki MaxObsActive, 200412Ki MaxObsWired, 892732Ki MaxObs(Act+Wir)
> Swap: . . . , 392328Ki MaxObsUsed
> 
> The build continues to run. I'll let you know how it goes.
> . . .

Just after libclang finished my odd top showed:

Mem:  . . . , 753672Ki MaxObsActive, 200412Ki MaxObsWired, 892736Ki MaxObs(Act+Wir)
Swap: . . . , 537588Ki MaxObsUsed

After liblldb:

Mem:  . . . , 753672Ki MaxObsActive, 200412Ki MaxObsWired, 899276Ki MaxObs(Act+Wir)
Swap: . . . , 537588Ki MaxObsUsed

Much later, after the lldb program had been built:

Mem:  . . . , 765700Ki MaxObsActive, 200412Ki MaxObsWired, 954116Ki MaxObs(Act+Wir)
Swap: . . . , 537588Ki MaxObsUsed

>>> World build completed on Mon Jan 18 19:10:08 PST 2021
>>> World built in 72960 seconds, ncpu: 4, make -j4

This was building from scratch what was already installed:

# ~/fbsd-based-on-what-freebsd-main.sh 
merge-base: 818390ce0ca539300dd15d7a817784f1e3f7a9b8
merge-base: CommitDate: 2021-01-13 21:27:44 +0000
4180404713ec (HEAD -> mm-src) mm-src snapshot for mm's patched build in git context.
818390ce0ca5 (freebsd/main, freebsd/HEAD, pure-src, main) arm64: fix early devmap assertion
FreeBSD OPiP2E_RPi2v11 13.0-CURRENT FreeBSD 13.0-CURRENT mm-src-c255938-g4180404713ec GENERIC-NODBG  arm armv7 1300135 1300135

This suggests that you should be able to build on the RPi2B v1.1,
using -j4, with appropriate configuration for what and how to build.


It is now building the matching kernel, my GENERIC-NODBG style.



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