On Mar 01 2013, Valdis.Kletnieks@vt.edu wrote:
X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.4-dev
On Fri, 01 Mar 2013 16:48:12 +0530, sandeep kumar said:
Don't you think it should throw panic()while calling the ioremap() itself. Because this sounds like a serious violation...
As you noted, it does give you a warning.
That's a kernel design philosophy - to reserve the panic() and BUG() calls for cases where it is *known* that proceeding further is unsafe or impossible. So the kernel does a panic() if it can't start /sbin/init at system boot-up - because without that, further progress is impossible. But once the system is up, we don't panic if PID 1 goes away - because it's possible that the user has an open window, and can su and at least do an orderly shutdown.
[snippage]
So that's the design philosophy of why it gives you a warning rather than a panic.
Great explanation. Thank you. I figured it would be something vaguely like this, but I'm very new to the *linux* kernel, so I wasn't going to try to answer. -- Arlie (Arlie Stephens arlie@worldash.org)