Re: Arm v7 RPi2 -current unresponsive to debugger escape during buildworld

On Thu, Nov 06, 2025 at 06:04:52AM -0800, bob prohaska wrote:
>For roughly the past year I've been seeing buildworld become unresponsive
>compiling -current on a Pi2 (armv7). The stoppages seem random, sometimes
>with no visible memory pressure, other times while swapping. The machine
>uses a USB mechanican hard drive for root and swap.

Hi Bob,

Now that https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=275030
is resolved, I was able to continue my obj-mounted-on-nfs build
and it completed:

--------------------------------------------------------------
>>> World build completed on Tue Nov 18 11:35:41 UTC 2025
>>> World built in 129259 seconds, ncpu: 4, make -j2
--------------------------------------------------------------

This is a buildworld with a nodebug kernel in order to get a
nodebug world+kernel, for 16:current (n281932)

Building on ufs2 on the rpi2 either with mmcsd or
connected to the usb2 port or doing things like git pull cause
(observationally) the filesystem to thrash, probably down
to resource starvation. This appears avoided using nfs mounts
for things like this. Resource starvation (possibly via a
different path, I expect memory) happens with -j3 or above for 
buildkernel/world even with nfs mounts.

The rpi2b was responsive rhroughout.
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