On (01/18/17 14:45), Sergey Senozhatsky wrote: [..] > > there is a function that clears @console_may_schedule out of > console_sem scope - console_flush_on_panic(). > so I *may be* can think about a worst case scenario of race > condition between > console_flush_on_panic()->console_may_schedule = 0 on panic CPU > and > console_unlock()->console_may_schedule = 1 from CPU that panic CPU > failed to stop (smp_send_stop() can return with secondary CPUs still being > online). what I mean, is that we can have, let's say, 2 CPUs spinning in console_unlock(), both with @console_may_schedule == 1 (because secondary CPU restores global @console_may_schedule value). now, suppose, we have misbehaving scheduler (well, we are in panic after all). secondary CPU will cond_resched() and may be lockup somewhere in the scheduler. which is fine, we don't care about that secondary CPU anyway. but the same can happen to panic CPU as well. what do you think? -ss -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
