> + /* > + * Avoid grouping on DSO/COW pages in specific and RO pages > + * in general, RO pages shouldn't hurt as much anyway since > + * they can be in shared cache state. > + */ OK, so that comment is crap. Its that you cannot work into RO pages and this RO pages don't establish a collaboration. > + if (page_mapcount(page) != 1 && !pmd_write(pmd)) > + flags |= TNF_NO_GROUP; Rik also noted that mapcount == 1 will trivially not form groups. This should indeed be so but I didn't test it without that clause. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>