On Tue, Jun 10, 2014 at 11:46:40PM +0300, Kirill A. Shutemov wrote: > Agreed. The patchset drops tail page refcounting. Very possibly I misread something or a later patch fixes this up, I just did a basic code review, but from the new code of split_huge_page it looks like it returns -EBUSY after checking the individual tail page refcounts, so it's not clear how that defines as "dropped". + for (i = 0; i < HPAGE_PMD_NR; i++) + tail_count += page_mapcount(page + i); + if (tail_count != page_count(page) - 1) { + BUG_ON(tail_count > page_count(page) - 1); + compound_unlock(page); + spin_unlock_irq(&zone->lru_lock); + return -EBUSY; -- 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>