From: Christoph Lameter Modify try_to_unmap to produce migration entries If we are trying to unmap an entry and do not have an associated swapcache entry but are doing migration then create a special migration entry pointing to the pfn. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton --- mm/rmap.c | 32 +++++++++++++++++++++----------- 1 files changed, 21 insertions(+), 11 deletions(-) diff -puN mm/rmap.c~swapless-v2-make-try_to_unmap-create-migration-entries mm/rmap.c --- devel/mm/rmap.c~swapless-v2-make-try_to_unmap-create-migration-entries 2006-04-13 17:09:55.000000000 -0700 +++ devel-akpm/mm/rmap.c 2006-04-13 17:09:55.000000000 -0700 @@ -620,17 +620,27 @@ static int try_to_unmap_one(struct page if (PageAnon(page)) { swp_entry_t entry = { .val = page_private(page) }; - /* - * Store the swap location in the pte. - * See handle_pte_fault() ... - */ - BUG_ON(!PageSwapCache(page)); - swap_duplicate(entry); - if (list_empty(&mm->mmlist)) { - spin_lock(&mmlist_lock); - if (list_empty(&mm->mmlist)) - list_add(&mm->mmlist, &init_mm.mmlist); - spin_unlock(&mmlist_lock); + + if (PageSwapCache(page)) { + /* + * Store the swap location in the pte. + * See handle_pte_fault() ... + */ + swap_duplicate(entry); + if (list_empty(&mm->mmlist)) { + spin_lock(&mmlist_lock); + if (list_empty(&mm->mmlist)) + list_add(&mm->mmlist, &init_mm.mmlist); + spin_unlock(&mmlist_lock); + } + } else { + /* + * Store the pfn of the page in a special migration + * pte. do_swap_page() will wait until the migration + * pte is removed and then restart fault handling. + */ + BUG_ON(!migration); + entry = make_migration_entry(page); } set_pte_at(mm, address, pte, swp_entry_to_pte(entry)); BUG_ON(pte_file(*pte)); _