Building libcamera on the RPiv4 seems to crash the RPi

[kbingham]

Not yet sure if this is a heat thing, a memory thing (this is a lower memory device) or because I have non-fully-tested firmwares loaded (from issue:1 here).

I can't attach a serial console at present so I can't easily see if there's a kernel panic. Just logging here for insight if anyone has any.

Next step will be reboot and get meson (ninja) to build only one job at a time.

[kbingham]

Aha - the SSH connection caught up.
It looks like it was indeed the OOM Killer running. So we'll need to be aware of memory constraints of people building on the target. Or find a way to improve that.

[  238.008270] [    868]  1000   868     7477     3567    90112      271             0 meson
[  238.008275] [    869]  1000   869      485        0    24576       19             0 sh
[  238.008281] [    870]  1000   870     1984      194    36864       39             0 c++
[  238.008286] [    871]  1000   871     1984      180    45056       39             0 c++
[  238.008291] [    872]  1000   872     1984      221    40960       39             0 c++
[  238.008297] [    873]  1000   873     1984      205    36864       39             0 c++
[  238.008302] [    874]  1000   874     1984      179    40960       39             0 c++
[  238.008307] [    876]  1000   876    37134    26973   315392     3109             0 cc1plus
[  238.008312] [    875]  1000   875    37952    27206   327680     3521             0 cc1plus
[  238.008317] [    877]  1000   877    37274    26721   319488     3449             0 cc1plus
[  238.008322] [    878]  1000   878    40488    29757   339968     3086             0 cc1plus
[  238.008327] [    879]  1000   879    34693    22755   294912     3812             0 cc1plus
[  238.008371] Out of memory: Kill process 878 (cc1plus) score 132 or sacrifice child
[  238.008384] Killed process 878 (cc1plus) total-vm:161952kB, anon-rss:116252kB, file-rss:2776kB, shmem-rss:0kB
[  238.019419] oom_reaper: reaped process 878 (cc1plus), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
[  373.493148] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0
[  373.493212] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0 - id 32 
[  373.493562] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0
[  373.493620] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0 - id 33 
[  373.504350] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0
[  373.504417] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0 - id 34 
[  373.520274] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0
[  373.520337] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0 - id 35 
[  373.536297] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0
[  373.536361] [drm:vc4_plane_set_blank [vc4]] *ERROR* vc4_crtc dd9e5840, plane de38fc40, blank 0 - id 36 

Note there are quite a few VC4 errors too - but I'll hopefully ignore those currently.

[kbingham]

Managed to build with ninja -j 1

[kbingham]

Compiles successfully on the RPi4 (4GB) but that's expected behaviour now I think.
I wonder if there's much we can do about this topic. I expect it's just a side effect of the larger memory footprint used by GCC compiling C++ and running 4 compiles in parallel, blowing past the 1GB mark.

It might not be very friendly to users building on a smaller memory system though. But the workaround will just be to prevent parallel builds.

[6by9]

We've had the same problem building OpenCV. A several of the jobs wanted around 650MB each, so even -j2 was enough to OOM the system as swap is only 100MB by default.

[kbingham]

A good reason to drive sales of the 4GB version :-D

Not a lot we can do here on the libcamera side for this topic (other than include the solution in an F.A.Q.), so I'll close this issue.

[meawoppl]

As a side note to this all, the build is -faster- and maybe 10x less memory hungry if you use clang ala:

CC=clang-11 CXX=clang++-11 meson build -Dpipelines=raspberrypi -Dtest=false -Dv4l2=true -Dpycamera=enabled
ninja -C build -j1

I was able to complete the build on a pi zero this way in about 20mins.