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-rw-r--r--mm/hugetlb.c30
1 files changed, 24 insertions, 6 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dcacc811e70..51c9e2c0164 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -286,6 +286,12 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
spin_lock(&hugetlb_lock);
if (page) {
+ /*
+ * This page is now managed by the hugetlb allocator and has
+ * no users -- drop the buddy allocator's reference.
+ */
+ put_page_testzero(page);
+ VM_BUG_ON(page_count(page));
nid = page_to_nid(page);
set_compound_page_dtor(page, free_huge_page);
/*
@@ -369,13 +375,14 @@ free:
enqueue_huge_page(page);
else {
/*
- * Decrement the refcount and free the page using its
- * destructor. This must be done with hugetlb_lock
+ * The page has a reference count of zero already, so
+ * call free_huge_page directly instead of using
+ * put_page. 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);
+ free_huge_page(page);
spin_lock(&hugetlb_lock);
}
}
@@ -394,12 +401,20 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages)
struct page *page;
unsigned long nr_pages;
+ /*
+ * We want to release as many surplus pages as possible, spread
+ * evenly across all nodes. Iterate across all nodes until we
+ * can no longer free unreserved surplus pages. This occurs when
+ * the nodes with surplus pages have no free pages.
+ */
+ unsigned long remaining_iterations = num_online_nodes();
+
/* Uncommit the reservation */
resv_huge_pages -= unused_resv_pages;
nr_pages = min(unused_resv_pages, surplus_huge_pages);
- while (nr_pages) {
+ while (remaining_iterations-- && nr_pages) {
nid = next_node(nid, node_online_map);
if (nid == MAX_NUMNODES)
nid = first_node(node_online_map);
@@ -417,6 +432,7 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages)
surplus_huge_pages--;
surplus_huge_pages_node[nid]--;
nr_pages--;
+ remaining_iterations = num_online_nodes();
}
}
}
@@ -664,9 +680,11 @@ int hugetlb_report_node_meminfo(int nid, char *buf)
{
return sprintf(buf,
"Node %d HugePages_Total: %5u\n"
- "Node %d HugePages_Free: %5u\n",
+ "Node %d HugePages_Free: %5u\n"
+ "Node %d HugePages_Surp: %5u\n",
nid, nr_huge_pages_node[nid],
- nid, free_huge_pages_node[nid]);
+ nid, free_huge_pages_node[nid],
+ nid, surplus_huge_pages_node[nid]);
}
/* Return the number pages of memory we physically have, in PAGE_SIZE units. */