[RFC PATCH 23/33] subarch TLB support

[davem at davemloft.net (David Miller)]

From: Chris Wright <chrisw at sous-sol.org>
Date: Tue, 18 Jul 2006 00:00:23 -0700

> +        BUG_ON(HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF) < 0);

Although it happens to work currently, I think we should get out of
the habit of putting operations with wanted side effects into BUG_ON()
calls.  The following is therefore more preferable:

	ret = HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF);
	BUG_ON(ret < 0);

If this were ASSERT() in userspace, turning off debugging at build
time would make the evaluations inside of the macro never occur.  It
is my opinion that BUG_ON() should behave similarly.