On Wed, Apr 21, 2010 at 10:53:05PM +0200, Johannes Weiner wrote: > Check below that loop. If it returns non-null, the first check is > whether it IS_ERR(). Indeed. > + * Returns the mapped (struct page *), %NULL if no mapping exists, or > + * an error pointer if there is a mapping to something not represented > + * by a page descriptor (see also vm_normal_page()). where exactly in vm_normal_page? Note I already checked vm_normal_page before sending the prev email and I didn't immediately see. I search return and they all return NULL except the return pfn_to_page(pfn), so is pfn_to_page that returns -EFAULT (the implementations I checked don't but there are plenty that I didn't check...). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>