diff options
| -rw-r--r-- | arch/mips/kernel/smp.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index af5cd3b8a3968..1d3a4b5019494 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -121,7 +121,19 @@ struct call_data_struct *call_data; * or are or have executed. * * You must not call this function with disabled interrupts or from a - * hardware interrupt handler or from a bottom half handler. + * hardware interrupt handler or from a bottom half handler: + * + * CPU A CPU B + * Disable interrupts + * smp_call_function() + * Take call_lock + * Send IPIs + * Wait for all cpus to acknowledge IPI + * CPU A has not responded, spin waiting + * for cpu A to respond, holding call_lock + * smp_call_function() + * Spin waiting for call_lock + * Deadlock Deadlock */ int smp_call_function (void (*func) (void *info), void *info, int retry, int wait) |