• David S. Miller's avatar
    sparc64: Add global register dumping facility. · 93dae5b7
    David S. Miller authored
    When a cpu really is stuck in the kernel, it can be often
    impossible to figure out which cpu is stuck where.  The
    worst case is when the stuck cpu has interrupts disabled.
    
    Therefore, implement a global cpu state capture that uses
    SMP message interrupts which are not disabled by the
    normal IRQ enable/disable APIs of the kernel.
    
    As long as we can get a sysrq 'y' to the kernel, we can
    get a dump.  Even if the console interrupt cpu is wedged,
    we can trigger it from userspace using /proc/sysrq-trigger
    
    The output is made compact so that this facility is more
    useful on high cpu count systems, which is where this
    facility will likely find itself the most useful :)
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    93dae5b7
sysrq.c 12.8 KB