On Wed, Sep 19, 2012 at 3:45 AM, Minchan Kim <minchan@xxxxxxxxxx> wrote:
> When I looked at zone stat mismatch problem, I found
> migrate_to_node doesn't decrease NR_ISOLATED_[ANON|FILE]
> if check_range fails.
>
> It can make system hang out.
>
> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> Cc: Mel Gorman <mgorman@xxxxxxx>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
> ---
> mm/mempolicy.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 3d64b36..6bf0860 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -953,16 +953,16 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
>
> vma = check_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
> flags | MPOL_MF_DISCONTIG_OK, &pagelist);
> - if (IS_ERR(vma))
> - return PTR_ERR(vma);
> -
> - if (!list_empty(&pagelist)) {
> + if (IS_ERR(vma)) {
> + err = PTR_ERR(vma);
> + goto out;
> + }
> + if (!list_empty(&pagelist))
> err = migrate_pages(&pagelist, new_node_page, dest,
> false, MIGRATE_SYNC);
> - if (err)
> - putback_lru_pages(&pagelist);
> - }
> -
> +out:
> + if (err)
> + putback_lru_pages(&pagelist);
Good catch!
This is a regression since following commit. So, I doubt we need
all or nothing semantics. Can we revert it instead? (and probably
we need more kind comment for preventing an accident)
commit 0def08e3acc2c9c934e4671487029aed52202d42
Author: Vasiliy Kulikov <segooon@xxxxxxxxx>
Date: Tue Oct 26 14:21:32 2010 -0700
mm/mempolicy.c: check return code of check_range
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