[FS#1349] System is unstable under high network load.

[LEDE Bugs]

The following task has a new comment added:

FS#1349 - System is unstable under high network load.
User who did this - moeller0 (moeller0)

----------
Mon Feb 12 11:39:14 2018 daemon.info pppd[1130]: No response to 5 echo-requests
Mon Feb 12 11:39:14 2018 daemon.notice pppd[1130]: Serial link appears to be disconnected.

This indicates that part of the problem is that due to high a load too many of PPP's LCP packets were either dropped or queued up too long. As a work-around for that issue you might want to try installing luci-app-sqm and sqm-scripts and intantiate sqm on pppoe-wan with download/ingress bandwidth set to say 85% of the nominal download bandwidth and upload/egress set to 95% of the nominal upload bandwidth. That should leave enough slack for PPP's LCP packets to not be crowded out.
This will not help with the kernel warning (it might make triggering that less likely but it will not address the warnings root cause, AFAIKT).
----------

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=1349#comment4313