Hi Johannes, I changed it like this. ------- Subject: transhuge isolate_migratepages() From: Andrea Arcangeli <aarcange@xxxxxxxxxx> It's not worth migrating transparent hugepages during compaction. Those hugepages don't create fragmentation. Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> --- diff --git a/mm/compaction.c b/mm/compaction.c --- a/mm/compaction.c +++ b/mm/compaction.c @@ -265,10 +265,23 @@ static unsigned long isolate_migratepage if (PageBuddy(page)) continue; + if (!PageLRU(page)) + continue; + + /* + * PageLRU is set, and lru_lock excludes isolation, + * splitting and collapsing (collapsing has already + * happened if PageLRU is set). + */ + if (PageTransHuge(page)) + continue; + /* Try isolate the page */ if (__isolate_lru_page(page, ISOLATE_BOTH, 0) != 0) continue; + VM_BUG_ON(PageTransCompound(page)); + /* Successfully isolated */ del_page_from_lru_list(zone, page, page_lru(page)); list_add(&page->lru, migratelist); -- 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>