On Mon, Jun 12, 2017 at 06:07:39PM +1000, Nicholas Piggin wrote: > > > This would probably be the right direction to go in, but it will take > > > slightly more I think. We first need to remove HAVE_NMI_WATCHDOG from > > > meaning that an arch has its own watchdog and does not want any HLD > > > stuff. I think with arch_touch_nmi_watchdog(), we can probably get there. > > > > > > While transitioning, we could add a new option instead, > > > > > > HAVE_ARCH_HARDLOCKUP_DETECTOR > > > > > > I think HAVE_PERF_EVENTS_NMI is sufficient to imply it will use the PERF > > > HLD. Possibly you could just change the name to be a bit more regular, > > > HAVE_PERF_NMI_HARDLOCKUP_DETECTOR > > > > Actually, I don't think I can just rename it as it has a specific use to let > > OPROFILE know the perf events are being NMI triggered as opposed to IRQ > > triggered. > > > > Though I like the direction you are going. Then arches either have one or > > the other. Or in the ppc case it is dependent on what ppc platform is being > > used. > > Okay, glad we're on the same page conceptually :) > > > > > Then the HARDLOCKUP_DETECTOR needs one or the other to work correctly with > > the arch/<arch>/Kconfig explicitly stating which one to use? > > Yeah I guess the arch would advertise it has the PERF_HLD or ARCH_HLD if > it provides its own. HARDLOCKUP_DETECTOR option would then depend on > one of the two being defined. > > I could try redoing the series with those changes to Kconfig and see how > it looks? Yeah, if you wouldn't mind. Sorry for dragging this out, but I feel like we are getting close to have this defined properly which would allow us to split the code up correctly in the future. Cheers, Don
