On Fri, Aug 14, 2020 at 05:36:36PM +0530, Sumit Garg wrote: > On Thu, 13 Aug 2020 at 15:47, Daniel Thompson > <daniel.thompson@xxxxxxxxxx> wrote: > > > > On Thu, Aug 13, 2020 at 02:55:12PM +0530, Sumit Garg wrote: > > > On Thu, 13 Aug 2020 at 05:38, Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > > > > On Wed, Aug 12, 2020 at 8:27 AM Doug Anderson <dianders@xxxxxxxxxxxx> wrote: > > > > > One > > > > > last worry is that I assume that most people testing (and even > > > > > automated testing labs) will either always enable NMI or won't enable > > > > > NMI. That means that everyone will be only testing one codepath or > > > > > the other and (given the complexity) the non-tested codepath will > > > > > break. > > > > > > > > > > > The current patch-set only makes this NMI to work when debugger (kgdb) > > > is enabled which I think is mostly suitable for development > > > environments. So most people testing will involve existing IRQ mode > > > only. > > > > > > However, it's very much possible to make NMI mode as default for a > > > particular serial driver if the underlying irqchip supports it but it > > > depends if we really see any production level usage of NMI debug > > > feature. > > > > The effect of this patch is not to make kgdb work from NMI it is to make > > (some) SysRqs work from NMI. I think that only allowing it to deploy for > > kgdb users is a mistake. > > > > Having it deploy automatically for kgdb users might be OK but it seems > > sensible to make this feature available for other users too. > > I think I wasn't clear enough in my prior reply. Actually I meant to > say that this patch-set enables NMI support for a particular serial > driver via ".poll_init()" interface and the only current user of that > interface is kgdb. > > So if there are other users interested in this feature, they can use > ".poll_init()" interface as well to enable it. Huh? We appear to speaking interchangably about users (people who sit in front of the machine and want a stack trace) and sub-systems ;-). I don't think other SysRq commands have quite such a direct relationship between the sub-system and the sysrq command. For example who are you expecting to call .poll_init() if a user wants to use the SysRq to provoke a stack trace? Daniel.
