The first two patches fix timeouts and deadlocks using NMI IPIs. The xmon deadlock fails with a timeout so it wasn't really noticed. The infinite timeout only hits when the system is in really bad shape or the sreset handler is broken somehow (e.g., running a guest and no KVM test in the handler).
Patch 1 is a necessary fix. Patch 2 is a bigger change, we could live without it because the sender will eventually time out and break the deadlock. Thanks, Nick Nicholas Piggin (3): powerpc/smp: Fix NMI IPI timeout powerpc/smp: Fix NMI IPI xmon timeout powerpc/smp: __smp_send_nmi_ipi static arch/powerpc/kernel/smp.c | 93 +++++++++++++-------------------------- 1 file changed, 30 insertions(+), 63 deletions(-) -- 2.19.2
