On Wed, 2018-05-02 at 13:07:26 UTC, Michael Ellerman wrote: > A CPU that gets stuck with interrupts hard disable can be difficult to > debug, as on some platforms we have no way to interrupt the CPU to > find out what it's doing. > > A stop-gap is to have the CPU save it's stack pointer (r1) in its paca > when it hard disables interrupts. That way if we can't interrupt it, > we can at least trace the stack based on where it last disabled > interrupts. > > In some cases that will be total junk, but the stack trace code should > handle that. In the simple case of a CPU that disable interrupts and > then gets stuck in a loop, the stack trace should be informative. > > We could clear the saved stack pointer when we enable interrupts, but > that loses information which could be useful if we have nothing else > to go on. > > Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Series applied to powerpc next. https://git.kernel.org/powerpc/c/7b08729cb272b4cd5c657cd5ac0ddd cheers
