The issue at hand is not permanent hangs. The issue is hangs
that return. Consider a clustering enviornment where the other nodes
have given up on the delayed node and clean up after it. When the hang
finally ends, the node still thinks it is "alive" and happily scribbles
to places it shouldn't.
udelay will not ever trigger the NMI watchdog, as it is running
on the processor, so the cpu timer will run happily. But as far as
everything higher up (kernel + userspace), the delay will be unnoticed
and bad things can happen.
Joel
--"I'm so tired of being tired, Sure as night will follow day. Most things I worry about Never happen anyway."
Joel Becker Senior Member of Technical Staff Oracle Corporation E-mail: joel.becker@oracle.com Phone: (650) 506-8127 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/