> > I think the SIGHUP must come from the new PID 1. > > I don't know if this will help you, however here is a program that I > wrote last year that starts a service in the initramfs, it survives > the systemd killing spree during the transition to the root > filesystem, a new copy of the program is started from the root > filesystem, the previous running state is passed from the initramfs to > the version started from the root filesystem, and the version started > from the initramfs is gracefully shut down. The program does not have > the SIGHUP issue that you describe, so maybe there's something here > that may help you. > > https://github.com/masneyb/early-service-example
Thanks very much for this pointer! I will take a closer look at your code since I would indeed prefer to start my process (and systemd-bootchart) in the initrd. I had tried doing that using "rdinit=" and did observe that the SIGHUP problem does not occur in that case (btw, it is SIGHUP followed by SIGCONT). For systemd-bootchart, after it does some initial set-up, it only reads files under /proc (and it keeps a directory stream to /proc open). Unfortunately, the switch-root operation somehow causes /proc/schedstat to become inaccessible, so systemd-bootchart is broken with "rdinit=" as well. -James M
