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hugetlb: use free_pool_huge_page() to return unused surplus pages 

Use the [modified] free_pool_huge_page() function to return unused
surplus pages.  This will help keep huge pages balanced across nodes
between freeing of unused surplus pages and freeing of persistent huge
pages [from set_max_huge_pages] by using the same node id "cursor". It
also eliminates some code duplication.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Lee Schermerhorn 2009-09-21 17:01:23 -07:00 committed by Linus Torvalds
parent e8c5c82498
commit 685f345708
1 changed files with 24 additions and 33 deletions
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57
mm/hugetlb.c
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@ -687,7 +687,7 @@ static int hstate_next_node_to_free(struct hstate *h)
* balanced over allowed nodes.
* Called with hugetlb_lock locked.
*/
static int free_pool_huge_page(struct hstate *h)
static int free_pool_huge_page(struct hstate *h, bool acct_surplus)
{
int start_nid;
int next_nid;
@ -697,13 +697,22 @@ static int free_pool_huge_page(struct hstate *h)
next_nid = start_nid;
do {
if (!list_empty(&h->hugepage_freelists[next_nid])) {
/*
* If we're returning unused surplus pages, only examine
* nodes with surplus pages.
*/
if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
!list_empty(&h->hugepage_freelists[next_nid])) {
struct page *page =
list_entry(h->hugepage_freelists[next_nid].next,
struct page, lru);
list_del(&page->lru);
h->free_huge_pages--;
h->free_huge_pages_node[next_nid]--;
if (acct_surplus) {
h->surplus_huge_pages--;
h->surplus_huge_pages_node[next_nid]--;
}
update_and_free_page(h, page);
ret = 1;
}
@ -884,22 +893,13 @@ free:
* When releasing a hugetlb pool reservation, any surplus pages that were
* allocated to satisfy the reservation must be explicitly freed if they were
* never used.
* Called with hugetlb_lock held.
*/
static void return_unused_surplus_pages(struct hstate *h,
unsigned long unused_resv_pages)
{
static int nid = -1;
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 = nr_online_nodes;
/* Uncommit the reservation */
h->resv_huge_pages -= unused_resv_pages;
@ -909,26 +909,17 @@ static void return_unused_surplus_pages(struct hstate *h,
nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
while (remaining_iterations-- && nr_pages) {
nid = next_node(nid, node_online_map);
if (nid == MAX_NUMNODES)
nid = first_node(node_online_map);
if (!h->surplus_huge_pages_node[nid])
continue;
if (!list_empty(&h->hugepage_freelists[nid])) {
page = list_entry(h->hugepage_freelists[nid].next,
struct page, lru);
list_del(&page->lru);
update_and_free_page(h, page);
h->free_huge_pages--;
h->free_huge_pages_node[nid]--;
h->surplus_huge_pages--;
h->surplus_huge_pages_node[nid]--;
nr_pages--;
remaining_iterations = nr_online_nodes;
}
/*
* 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.
* free_pool_huge_page() will balance the the frees across the
* on-line nodes for us and will handle the hstate accounting.
*/
while (nr_pages--) {
if (!free_pool_huge_page(h, 1))
break;
}
}
@ -1268,7 +1259,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
min_count = max(count, min_count);
try_to_free_low(h, min_count);
while (min_count < persistent_huge_pages(h)) {
if (!free_pool_huge_page(h))
if (!free_pool_huge_page(h, 0))
break;
}
while (count < persistent_huge_pages(h)) {