On Thu, Jun 14, 2018 at 11:41:44AM +1000, Nicholas Piggin wrote: > On Wed, 13 Jun 2018 18:19:01 -0700 > Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx> wrote: > > > On Wed, Jun 13, 2018 at 10:43:24AM +0200, Peter Zijlstra wrote: > > > On Tue, Jun 12, 2018 at 05:57:34PM -0700, Ricardo Neri wrote: > > > > The current default implementation of the hardlockup detector assumes that > > > > it is implemented using perf events. > > > > > > The sparc and powerpc things are very much not using perf. > > > > Isn't it true that the current hardlockup detector > > (under kernel/watchdog_hld.c) is based on perf? > > arch/powerpc/kernel/watchdog.c is a powerpc implementation that uses > the kernel/watchdog_hld.c framework. > > > As far as I understand, > > this hardlockup detector is constructed using perf events for architectures > > that don't provide an NMI watchdog. Perhaps I can be more specific and say > > that this synthetized detector is based on perf. > > The perf detector is like that, but we want NMI watchdogs to share > the watchdog_hld code as much as possible even for arch specific NMI > watchdogs, so that kernel and user interfaces and behaviour are > consistent. > > Other arch watchdogs like sparc are a little older so they are not > using HLD. You don't have to change those for your series, but it > would be good to bring them into the fold if possible at some time. > IIRC sparc was slightly non-trivial because it has some differences > in sysctl or cmdline APIs that we don't want to break. > > But powerpc at least needs to be updated if you change hld apis. I will look into updating at least the powerpc implementation as part of these changes. Thanks and BR, Ricardo -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
