What's new

AT-AC86U Core 0 is Missing

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

CaptnDanLKW

Senior Member
AT-AC86U on 384.15

Well, this is new. I noticed that I only have Core #1 listed in the GUI. Assuming it was a browser issue, I cleared cache and tried a different one. Same issue.

In logs I see these.

Code:
Mar 13 08:00:17 RTAC86U kernel: thermal cooling_device1: turn off CPU#1
Mar 13 08:00:17 RTAC86U kernel: IRQ6 no longer affine to CPU1
Mar 13 08:00:17 RTAC86U kernel: IRQ28 no longer affine to CPU1
Mar 13 08:00:17 RTAC86U kernel: IRQ29 no longer affine to CPU1
Mar 13 08:00:17 RTAC86U kernel: IRQ30 no longer affine to CPU1
Mar 13 08:00:17 RTAC86U kernel: CPU1: shutdown
Mar 13 08:00:17 RTAC86U kernel: process 1303 (dcd) no longer affine to cpu1
Mar 13 08:00:19 RTAC86U kernel: process 23416 (dcd) no longer affine to cpu1
Mar 13 08:00:21 RTAC86U kernel: process 1301 (dcd) no longer affine to cpu1
Mar 13 08:00:39 RTAC86U kernel: process 1305 (dcd) no longer affine to cpu1
Mar 13 08:10:04 RTAC86U kernel: process 1300 (dcd) no longer affine to cpu1

Looks like networkmap and watchdog processes are running constant (but not cpu crushing)
upload_2020-3-13_9-52-29.png


and its hot
upload_2020-3-13_9-54-16.png


Just to be sure, I checked /proc/cpuinfo
Code:
@RTAC86U:/tmp# cat /proc/cpuinfo
processor       : 0
BogoMIPS        : 100.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32
CPU implementer : 0x42
CPU architecture: 8
CPU variant     : 0x0
CPU part        : 0x100
CPU revision    : 0

I'm sure a reboot will bring it back but this seems troublesome. Been running 384.13, 14 and 15 for about 5 months on my RT-AC86U for a while, been on .15 since release. Normally my uptime is great but i've been experimenting with SmartConnect and different WiFi settings as I look to address an unrelated issue.

Thoughts?
 
Last edited:
Based on this, the CPU is overheating, and one of the cores got shut down to prevent damage. Since only the CPU is truly abnormal, I'd say it's RMA time, unless you feel like opening it, and making sure the heatsink is properly installed.
 
Experimenting = changing common settings, something that shouldn't freak out the router but rebooting was my next step in troubleshooting.

Rebooted, system came back up with only 1 core, then about 5 minutes later the other one appeared.
Code:
Mar 13 10:08:53 RTAC86U kernel: thermal cooling_device1: turn on CPU#1
Mar 13 10:08:53 RTAC86U kernel: CPU1: Booted secondary processor
Mar 13 10:08:53 RTAC86U kernel: Detected VIPT I-cache on CPU1
Mar 13 10:08:53 RTAC86U kernel: IRQ6: affinity change from 0 to 1

and temperatures are back to normal.

I'll keep my eye on it, but it 'feels' like a software bug, perhaps in a closed source component that didn't exactly translate to a visible user or kernel process but something was in a race condition.
 

Similar threads

Latest threads

Support SNBForums w/ Amazon

If you'd like to support SNBForums, just use this link and buy anything on Amazon. Thanks!

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top