DR> That's not a precedent, there's a big difference between the DR> performance of gup_fast(), where we can't spare an additional DR> compare and branch, and walk_page_range(). VM_BUG_ON() is typically DR> used in situations where a debug kernel has been built, including DR> CONFIG_DEBUG_VM, and the check helps to isolate a problem that would DR> be otherwise difficult to find. Okay, fair enough. I was trying to stay in line with the other conventions, knowing that the check would only be done with CONFIG_DEBUG_VM enabled. I'd rather just make it always do the check in walk_page_range(). Does that sound reasonable? -- Dan Smith IBM Linux Technology Center email: danms@xxxxxxxxxx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>