Re: kern/57171: altqd takes 100% of a CPU when daemon is stopped

[BERTRAND Joël <joel.bertrand%systella.fr@localhost>]

Taylor R Campbell a écrit :
> The following reply was made to PR kern/57171; it has been noted by GNATS.
> 
> From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
> To: =?UTF-8?Q?BERTRAND_Jo=c3=abl?= <joel.bertrand%systella.fr@localhost>
> Cc: gnats-bugs%NetBSD.org@localhost
> Subject: Re: kern/57171: altqd takes 100% of a CPU when daemon is stopped
> Date: Fri, 6 Jan 2023 19:28:49 +0000
> 
>  Can you do the following:
>  
>  1. When altqd is hanging and taking 100% CPU, hit ^T at the terminal
>     and show what it prints?

netbsd-test1# /etc/rc.d/altqd onestart
Starting altqd.
netbsd-test1# /etc/rc.d/altqd onestop
Stopping altqd.
[ 1918.6360379] load: 0.08  cmd: sleep 2081 [nanoslp] 0.00u 0.00s 0% 1520k
sleep: Between -1 and 0 seconds left out of the original 0 and a bit

>  2. Install the debug.tgz set (or debug.tar.xz) in the VM, try
>     attaching gdb again, and do `bt' and `info locals'?

netbsd-test1# gdb -p 1779
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Attaching to process 1779
Reading symbols from /usr/sbin/altqd...
(No debugging symbols found in /usr/sbin/altqd)
Reading symbols from /usr/lib/libutil.so.7...
Reading symbols from /usr/libdata/debug//usr/lib/libutil.so.7.24.debug...
Reading symbols from /usr/lib/libm.so.0...
Reading symbols from /usr/libdata/debug//usr/lib/libm.so.0.12.debug...
Reading symbols from /usr/lib/libc.so.12...
Reading symbols from /usr/libdata/debug//usr/lib/libc.so.12.220.debug...
Reading symbols from /usr/libexec/ld.elf_so...
Reading symbols from /usr/libdata/debug//libexec/ld.elf_so.debug...
[Switching to LWP 1779 of process 1779]
0x00000000a9e0564b in qop_clear ()
(gdb) bt
#0  0x00000000a9e0564b in qop_clear ()
#1  0x00000000a9e05774 in qop_delete_if ()
#2  0x00000000a9e058c6 in qcmd_destroyall ()
#3  0x00000000a9e12c45 in main ()
(gdb) info locals
No symbol table info available.
(gdb)

	Please not that there is no altqd or altqd.debug in debug.tar.xz.

>  It might be stuck in logic in userland.  Possible there's some bug
>  with the data structure management in qop.c that sends it into an
>  infinite loop.
>  
>