On Mon, 10 Aug 2015, David Vrabel wrote:

On 10/08/15 13:03, Stefano Stabellini wrote:

quoted

On Fri, 7 Aug 2015, Julien Grall wrote:

quoted

-	rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
-	return rc < 0 ? rc : err;
+	for (i = 0; i < nr_gfn; i++) {
+		if ((i % XEN_PFN_PER_PAGE) == 0) {
+			page = pages[i / XEN_PFN_PER_PAGE];

If this function is going to be called very frequently you might want to
consider using a shift instead.

    page = pages[i >> 4];

With an appropriate macro of course.

This change isn't necessary.  Compilers already turn divides into
suitable shifts.

The ARM compiler I used last time I tested this did not, but that was 1
or 2 years ago. In any case to be clear this change is not required.