do_migrate_pages() can return the number of pages not migrated. Because migrate_pages() syscall return this value directly, migrate_pages() syscall may return the number of pages not migrated. In fail case in migrate_pages() syscall, we should return error value. So change err to -EBUSY Additionally, Correct comment above do_migrate_pages() Signed-off-by: Joonsoo Kim <js1304@xxxxxxxxx> Cc: Sasha Levin <levinsasha928@xxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx> diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 1d771e4..0732729 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -948,7 +948,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest, * Move pages between the two nodesets so as to preserve the physical * layout as much as possible. * - * Returns the number of page that could not be moved. + * Returns error or the number of pages not migrated. */ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, const nodemask_t *to, int flags) @@ -1382,6 +1382,8 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, err = do_migrate_pages(mm, old, new, capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); + if (err > 0) + err = -EBUSY; mmput(mm); out: -- 1.7.9.5 -- 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>