[PATCH 04/12] mm: alloc_contig_freed_pages() added

On Thu, 2011-03-31 at 15:24 -0400, Steven Rostedt wrote:

On Thu, Mar 31, 2011 at 08:58:03AM -0700, Dave Hansen wrote:

quoted

On Thu, 2011-03-31 at 15:16 +0200, Marek Szyprowski wrote:

quoted

+unsigned long alloc_contig_freed_pages(unsigned long start, unsigned long end,
+                                      gfp_t flag)
+{
+       unsigned long pfn = start, count;
+       struct page *page;
+       struct zone *zone;
+       int order;
+
+       VM_BUG_ON(!pfn_valid(start));

This seems kinda mean.  Could we return an error?  I understand that
this is largely going to be an early-boot thing, but surely trying to
punt on crappy input beats a full-on BUG().

	if (!pfn_valid(start))
		return -1;

But still keep the warning?

	if (WARN_ON(!pfn_valid(start))
		return -1;

Sure.  You might also want to make sure you're respecting __GFP_NOWARN
if you're going to do that, or maybe just warn once per boot.


-- Dave