On ppc64 hardware (and IBM ppc32 hardware) there is typically a reset button that causes a non-maskable reset. This vectors all cpus into a single function. I would like to code it to trap into kdb when I do this.
I have found that kdb doesn't seem to like this with any of the currently defined "reasons." All the processors in this case are going to call into kdb at precisely the same time. I currently have code in the ppc64 reset path that lets the first processor into kdb (KDB_REASON_ENTER) and forces the rest to resume so that kdb can eventually snag them with its own IPI. I don't like this because I lose perfectly good state, and we don't have any other NMI to stop "stuck" processors :(. Anyway, the point of this e-mail was to make sure I am not missing something. Otherwise I can code up a new KDB_REASON_RESET or such. -todd
