From 90036ee5938d89638e80f4d0d0700d0f2dbd4a6a Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Thu, 16 Mar 2006 23:03:59 -0800 Subject: [PATCH] [PATCH] page migration: Fail with error if swap not setup Currently the migration of anonymous pages will silently fail if no swap is setup. This patch makes page migration functions check for available swap and fail with -ENODEV if no swap space is available. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 2a8206009422..b21869a39f0b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -330,9 +330,19 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end, int err; struct vm_area_struct *first, *vma, *prev; - /* Clear the LRU lists so pages can be isolated */ - if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) + if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) { + /* Must have swap device for migration */ + if (nr_swap_pages <= 0) + return ERR_PTR(-ENODEV); + + /* + * Clear the LRU lists so pages can be isolated. + * Note that pages may be moved off the LRU after we have + * drained them. Those pages will fail to migrate like other + * pages that may be busy. + */ lru_add_drain_all(); + } first = find_vma(mm, start); if (!first) -- 2.30.2