On 2019-03-07, Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> wrote: >>> If the serial console is a really slow one and we have a CPU in >>> atomic context spinnig on prb_lock, while the prb_lock is always >>> acquired by other CPUs, then it may look like a lock-up scenario. >> >> When the console is constantly printing messages, I wouldn't say that >> looks like a lock-up scenario. It looks like the system is busy >> printing critical information to the console (which it is). > > What if we have N tasks/CPUs calling printk() simultaneously? Then they take turns printing their messages to the console, spinning until they get their turn. This still is not and does not look like a lock-up. But I think you already know this, so I don't understand the reasoning behind asking the question. Maybe you could clarify what you are getting at. John Ogness
