Commit af767cbd authored Oct 16, 2007 by Adam Litke Committed by Linus Torvalds Oct 16, 2007

hugetlb: fix dynamic pool resize failure case



When gather_surplus_pages() fails to allocate enough huge pages to satisfy
the requested reservation, it frees what it did allocate back to the buddy
allocator.  put_page() should be called instead of update_and_free_page()
to ensure that pool counters are updated as appropriate and the page's
refcount is decremented.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Dave Hansen <haveblue@us.ibm.com>
Cc: David Gibson <hermes@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Ken Chen <kenchen@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 63b4613c

mm/hugetlb.c

+11 −2

Original line number	Original line	Diff line number	Diff line
	@@ -302,8 +302,17 @@ static int gather_surplus_pages(int delta)
	list_del(&page->lru);		list_del(&page->lru);
	if ((--needed) >= 0)		if ((--needed) >= 0)
	enqueue_huge_page(page);		enqueue_huge_page(page);
	else		else {
	update_and_free_page(page);		/*
			* Decrement the refcount and free the page using its
			* destructor. This must be done with hugetlb_lock
			* unlocked which is safe because free_huge_page takes
			* hugetlb_lock before deciding how to free the page.
			*/
			spin_unlock(&hugetlb_lock);
			put_page(page);
			spin_lock(&hugetlb_lock);
			}
	}		}

	return ret;		return ret;