On Thu, Apr 18, 2013 at 03:13:55PM +0800, Lin Ming wrote: > I encounter a problem that cpu stuck with irq disabled, which is known > as hard lockup. > I know there is NMI hard lockup detector for x86, which can dump the > back trace of the hard lockup. > > Is there any similar feature for MIPS? No, there isn't, unfortunately. This is because on MIPS an NMI is very different from for example x86. An NMI goes straight to a firmware address and most firmware implementations don't provided a suitable hook for an OS to gain control back from an NMI. Generally on MIPS NMIs are used to signal catastrophic problems, things like a machine check exception but external to the CPU. One of the notable exceptions is Octeon where (see the Octeon watchdog driver) an OS can regain control after an NMI. Malta and SGI IP27 also have somewhat useful NMIs. Ralf
