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

Hi,

To me it sounds like your machine is overwhelmed by swapping.

Try -j1 buildworld.

Regards,
Ronald.

 
Van: bob prohaska <fbsd@www.zefox.net>
Datum: donderdag, 6 november 2025 15:04
Aan: freebsd-arm@freebsd.org
CC: freebsd-current@freebsd.org
Onderwerp: Arm v7 RPi2 -current unresponsive to debugger escape during buildworld
> 
> 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.
> 
> Numerous attemps to use enter-tilda-control-B to get into the debugger
> have failed, with absolutely no response. In the most recent case the
> disk activity light was flashing rapidly, a relatively uncommon event.
> The frozen top window showed ~312 MB swap in use, less than half of
> the maximum commonly seen for a -j3 buildworld.
> 
> Looking at the log file after power-cycling it appeared to have last
> updated the previous evening, so it seems unlikely it got stuck on
> a core dump. Reboot was uneventful, with fsck completing successfully.
> Buildworld has been restarted, it'll pick up where it left off.
> 
> The last entries in the buildworld log file were:
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Sema/SemaTemplateInstantiateDecl.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Sema/SemaTemplateVariadic.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Sema/SemaType.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Sema/SemaWasm.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Sema/SemaX86.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Sema/TypeLocBuilder.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Serialization/ASTCommon.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Serialization/ASTReader.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Serialization/ASTReaderDecl.pico
> Building /usr/obj/usr/src/arm.armv7/lib/clang/libclang/Serialization/ASTReaderStmt.pico
> 
> No warnings or errors of any kind appear on the serial console, ever.
> 
> Is there some other way to get at debugger services in a case like this?
> I understand it's possible to run programs under debugger "supervision"
> at the time of invocation, but would that provide any extra avenues to
> find out what's going wrong? I think not, but I'd like very much to gather
> some useful information toward a fix.
> 
> Thanks for reading,
> 
> bob prohaska
> 
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