On Thursday 13 February 2020 21:32:30 Jon Elson wrote: > On 02/13/2020 04:53 PM, Thomas D. Dean wrote: > > I shut down the system last night. > > > > I can boot debian 7 (sda) and run linuxcnc from the > > distro. Everything comes up and seems normal. > > > > But, on boot into debian 10 (sdb), it drops into the > > console login. I can startx, but, the display is > > background only. I can switch to another console, > > ctl-alt-F3, and start some xterms, then switch back to X, > > alt-F1, and the xterms are there. I can do most things. > > I can NOT see dmesg as a normal user. > > > > > dmesg > > > > dmesg: read kernel buffer failed: Operation not permitted > > > > Strange. > > I'm taking a wild guess, but maybe the system did an > automatic update that included a kernel update sometime in > the past, but this required a reboot to load the new kernel. > LinuxCNC is compiled/linked against a specific kernel, and > so a kernel update will cause it to not run anymore.
I didn't find that in my last rpi4 kernel rebuild that was actually an improved latency-test, from about 50 u-secs down to 16 u-secs. lcnc built as uspace always on the rpi4. Thinking about new kernels, I probably should go back and do a make headers_install too. > So, > you really want to turn off automatic updates, or at least make > sure that kernel updates require manual approval. > > Jon > Exactly why I "pin" them. The offered replacements are never "realtime" In fact that potential for such cross contamination alone should be considered an apt bug. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
