FreeBSD 13.0-RC4 and Nginx process "stuck" during restart

[Mark Johnston]

On Mon, Mar 29, 2021 at 10:57:09PM +0300, Christos Chatzaras wrote:
> Hello,
> 
> 
> I upgrade from 12.2 to 13.0-RC4 and I notice a strange issue with Nginx.
> 
> When I run "service nginx restart" in some (random) servers it doesn't complete the restart and it "stucks" at "Waiting for PIDS: 20536." .
> 
> I can kill the 20536 process and then restart completes.
> 
> 
> procstat -kk 20536:
> 
>   PID    TID COMM                TDNAME              KSTACK
> 63094 100505 nginx               -                   mi_switch+0xc1 sleepq_catch_signals+0x2e6 sleepq_wait_sig+0x9 _sleep+0x1be kern_sigsuspend+0x164 sys_sigsuspend+0x31 amd64_syscall+0x10c fast_syscall_common+0xf8 
> 
> 
> I found this commit:
> 
> https://cgit.freebsd.org/src/commit/?id=dbec10e08808e375365fb2a2462f306e0cdfda32 <https://cgit.freebsd.org/src/commit/?id=dbec10e08808e375365fb2a2462f306e0cdfda32>
> 
> Could this be related? If yes can we have the patch in releng/13.0 ?

I think it is hard to say without some testing.  Are you able to verify
that backporting the patch fixes the hangs?