Re: kernel: sonewconn: pcb 0xfffff8002b255a00 (local:/var/run/devd.seqpacket.pipe): Listen queue overflow: 1 already in queue awaiting acceptance (60 occurrences), ?

From: Gary Jennejohn <garyj_at_gmx.de>
Date: Tue, 20 Jun 2023 07:41:08 UTC 
On Tue, 20 Jun 2023 06:25:05 +0100
Graham Perrin <grahamperrin@freebsd.org> wrote:

> Please, what's the meaning of the sonewconn lines?
>

sonewconn is described in socket(9).  Below a copy/paste of the description
from socket(9):

     Protocol implementations can use sonewconn() to create a socket and
     attach protocol state to that socket.  This can be used to create new
     sockets available for soaccept() on a listen socket.  The returned socket
     has a reference count of zero.

Apparently there was already a listen socket in the queue which had not been
consumed by soaccept() when a new sonewconn() call was made.

Anyway, that's my understanding.  Might be wrong.

> % tail -f -n 0 /var/log/messages
> Jun 20 04:08:41 mowa219-gjp4-8570p-freebsd su[4159]: grahamperrin to
> root on /dev/pts/6
> Jun 20 04:12:20 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: Cannot
> fetch process 4501 command line (command 'sysctl')
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: lock order reversal:
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel:  1st
> 0xfffffe0103db30e0 filedesc structure (filedesc structure, sx) @
> /usr/src/sys/kern/kern_descrip.c:1397
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel:  2nd
> 0xfffff80001df8930 devfs (devfs, lockmgr) @
> /usr/src/sys/kern/vfs_subr.c:6244
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: lock order filedesc
> structure -> devfs attempted at:
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #0 0xffffffff80bc4573
> at witness_checkorder+0xbb3
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #1 0xffffffff80b21265
> at lockmgr_xlock+0x55
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #2 0xffffffff80c5e4b4
> at _vn_lock+0x54
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #3 0xffffffff80afd13b
> at knlist_remove_kq+0x8b
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #4 0xffffffff80c517d4
> at filt_vfsdetach+0x24
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #5 0xffffffff80afdad0
> at knote_fdclose+0x180
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #6 0xffffffff80af4f2c
> at closefp_impl+0x9c
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #7 0xffffffff8104d8e0
> at amd64_syscall+0x140
> Jun 20 04:30:25 mowa219-gjp4-8570p-freebsd kernel: #8 0xffffffff81020b3b
> at fast_syscall_common+0xf8
> Jun 20 04:34:26 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: heartbeat
> clock: woke up 1346787 microseconds later than expected (can be due to
> system load or the CLOCK_REALTIME set to the future).
> Jun 20 04:35:38 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: Cannot
> fetch process 6471 command line (command 'sysctl')
> Jun 20 04:55:30 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: Cannot
> fetch process 7697 command line (command 'sysctl')
> Jun 20 05:07:16 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: Cannot
> fetch process 8416 command line (command 'sysctl')
> Jun 20 05:17:42 mowa219-gjp4-8570p-freebsd kernel: sonewconn: pcb
> 0xfffff8002b255a00 (local:/var/run/devd.seqpacket.pipe): Listen queue
> overflow: 1 already in queue awaiting acceptance (1 occurrences), euid
> 0, rgid
> 0, jail 0
> Jun 20 05:18:42 mowa219-gjp4-8570p-freebsd kernel: sonewconn: pcb
> 0xfffff8002b255a00 (local:/var/run/devd.seqpacket.pipe): Listen queue
> overflow: 1 already in queue awaiting acceptance (60 occurrences), euid
> 0, rgi
> d 0, jail 0
> Jun 20 05:18:56 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: Cannot
> fetch process 9359 command line (command 'git')
> Jun 20 05:19:42 mowa219-gjp4-8570p-freebsd kernel: sonewconn: pcb
> 0xfffff8002b255a00 (local:/var/run/devd.seqpacket.pipe): Listen queue
> overflow: 1 already in queue awaiting acceptance (60 occurrences), euid
> 0, rgi
> d 0, jail 0
> Jun 20 05:20:03 mowa219-gjp4-8570p-freebsd apps.plugin[3178]: Cannot
> fetch process 9602 command line (command 'cat')
> Jun 20 05:20:43 mowa219-gjp4-8570p-freebsd kernel: sonewconn: pcb
> 0xfffff8002b255a00 (local:/var/run/devd.seqpacket.pipe): Listen queue
> overflow: 1 already in queue awaiting acceptance (60 occurrences), euid
> 0, rgi
> d 0, jail 0
> ^C
> % sudo sysctl kern.sched.pick_short=1
> grahamperrin's password:
> kern.sched.pick_short: 0 -> 1
> % sudo sysctl kern.sched.preempt_thresh=224
> kern.sched.preempt_thresh: 48 -> 224
> % uptime
> 6:23a.m.  up  2:24, 7 users, load averages: 0.78, 1.24, 1.34
> % uname -aKU
> FreeBSD mowa219-gjp4-8570p-freebsd 14.0-CURRENT FreeBSD 14.0-CURRENT #7
> main-n263630-ab3e6234ab6e-dirty: Sun Jun 18 14:56:48 BST 2023
> grahamperrin@mowa219-gjp4-8570p-freebsd:/usr/obj/usr/src/amd64.amd64/sys/GEN
> ERIC amd64 1400090 1400090
> %
>
>


--
Gary Jennejohn