Cc: Nick Piggin <npiggin@...>, Linux Memory Management <linux-mm@...>, Linux Kernel <linux-kernel@...>, Benjamin Herrenschmidt <benh@...>, Ingo Molnar <mingo@...>
On Tue, Mar 06, 2007 at 10:51:01PM -0800, Andrew Morton wrote:
The major vs. minor fault accounting patch that introduced the argument
didn't make non-NULL type arguments a requirement. It's essentially an
optional second return value and the NULL pointer represents the caller
choosing to ignore it. I'm not sure I actually liked that aspect of it,
but that's how it ended up going in. I think it had something to do
with driver churn clashing with the sweep at the time of the merge. I'd
rather the argument be mandatory and defaulted to VM_FAULT_MINOR.
It's something of a non-answer, though, since it only discusses a
convention as opposed to reviewing specific callers of filemap_nopage().
NULL type arguments to ->nopage() are rare at most, and could be easily
eliminated, at least for in-tree drivers.
egrep -nr 'nopage.*NULL' . 2>/dev/null | grep -v '^Bin' on a current
git tree yields zero matches.
-- wli
-
