Skip to content

Commit

Permalink
mm: numa: ensure anon_vma is locked to prevent parallel THP splits
Browse files Browse the repository at this point in the history
The anon_vma lock prevents parallel THP splits and any associated
complexity that arises when handling splits during THP migration.  This
patch checks if the lock was successfully acquired and bails from THP
migration if it failed for any reason.

Signed-off-by: Mel Gorman <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: Alex Thorlton <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
Mel Gorman authored and torvalds committed Dec 19, 2013
1 parent 0c5f83c commit c3a489c
Showing 1 changed file with 7 additions and 0 deletions.
7 changes: 7 additions & 0 deletions mm/huge_memory.c
Original file line number Diff line number Diff line change
Expand Up @@ -1359,6 +1359,13 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
goto out_unlock;
}

/* Bail if we fail to protect against THP splits for any reason */
if (unlikely(!anon_vma)) {
put_page(page);
page_nid = -1;
goto clear_pmdnuma;
}

/*
* Migrate the THP to the requested node, returns with page unlocked
* and pmd_numa cleared.
Expand Down

0 comments on commit c3a489c

Please sign in to comment.