On Mon, Nov 16, 2020 at 11:53:38AM -0500, Alberto Sentieri wrote: > The objective of this email is to report the current status of my findings. > > I loaded netconsole on both machines I was having problems with. I tried 3 > times on the machine with kernel 5.0.0-37 and twice with on the machine with > kernel 5.3.0-62. Each attempt consisted of running the program which lock > the kernel until it locked (about 3 minutes after stating the program). The > referred program had the "semphore code" commented out. Nothing was sent to > netconsole on all the 5 attempts I made when the kernel locked. > > Just to be clear about my use of netconsole, before loading the netconsole > kernel module, I ran "dmesg -n 8". When netconsole module was loaded I could > clearly see about 9 message lines on the computer receiving the netconsole > messages telling me that netconsole was loaded (and how it was configured), > so no doubts about the correct netconsole setup. The "netconsole server" was > a machine on the same local network. > > My next attempt will be to compile kernel 5.9, as you suggest, and try it. While this may not generate any useful information, one way to create a bunch of log output while running your test is to set the usbfs_snoop module parameter for usbcore to true. You can also enable dynamic debugging for usbcore, although in a stable environment like yours it probably won't produce much output. Alan Stern
