Re: [PATCH v3 11/12] mm/gup_benchmark: support pin_user_pages() and related calls

On Mon, Feb 03, 2020 at 01:17:40PM -0800, John Hubbard wrote:

On 2/3/20 5:58 AM, Kirill A. Shutemov wrote:
...

quoted

quoted

@@ -19,6 +21,48 @@ struct gup_benchmark {
 	__u64 expansion[10];	/* For future use */
 };
 
+static void put_back_pages(unsigned int cmd, struct page **pages,
+			   unsigned long nr_pages)
+{
+	int i;
+
+	switch (cmd) {
+	case GUP_FAST_BENCHMARK:
+	case GUP_LONGTERM_BENCHMARK:
+	case GUP_BENCHMARK:
+		for (i = 0; i < nr_pages; i++)

'i' is 'int' and 'nr_pages' is 'unsigned long'.
There's space for trouble :P

Yes, I've changed it to "unsigned int", thanks.

I'm confused. If nr_pages is more than UINT_MAX, this is endless loop.
Hm?

-- 
 Kirill A. Shutemov