Re: 2.5.72-mm1

William Lee Irwin III (wli@holomorphy.com)
Wed, 18 Jun 2003 14:24:25 -0700


On Tue, Jun 17, 2003 at 01:40:44AM -0700, Andrew Morton wrote:
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.5/2.5.72/2.5.72-mm1/
> . A fairly large batch of changes in the block request allocation,
> batching and throttling code. To address worst-case latency, improve
> throughput in benchmarky loads, etc.
> . The memory debugging patch which unmaps pages and large slab objects
> from the kernel virtual address space is back.

The following patch implements node-local memory allocation support for
hugetlb. Successfully tested on NUMA-Q.

-- wli

diff -prauN linux-2.5.72/arch/i386/mm/hugetlbpage.c htlb-2.5.72-1/arch/i386/mm/hugetlbpage.c
--- linux-2.5.72/arch/i386/mm/hugetlbpage.c 2003-06-16 21:20:22.000000000 -0700
+++ htlb-2.5.72-1/arch/i386/mm/hugetlbpage.c 2003-06-17 14:04:05.000000000 -0700
@@ -24,9 +24,41 @@ static long htlbpagemem;
int htlbpage_max;
static long htlbzone_pages;

-static LIST_HEAD(htlbpage_freelist);
+static struct list_head hugepage_freelists[MAX_NUMNODES];
static spinlock_t htlbpage_lock = SPIN_LOCK_UNLOCKED;

+static void enqueue_huge_page(struct page *page)
+{
+ list_add(&page->list,
+ &hugepage_freelists[page_zone(page)->zone_pgdat->node_id]);
+}
+
+static struct page *dequeue_huge_page(void)
+{
+ int nid = numa_node_id();
+ struct page *page = NULL;
+
+ if (list_empty(&hugepage_freelists[nid])) {
+ for (nid = 0; nid < MAX_NUMNODES; ++nid)
+ if (!list_empty(&hugepage_freelists[nid]))
+ break;
+ }
+ if (nid >= 0 && nid < MAX_NUMNODES && !list_empty(&hugepage_freelists[nid])) {
+ page = list_entry(hugepage_freelists[nid].next, struct page, list);
+ list_del(&page->list);
+ }
+ return page;
+}
+
+static struct page *alloc_fresh_huge_page(void)
+{
+ static int nid = 0;
+ struct page *page;
+ page = alloc_pages_node(nid, GFP_HIGHUSER, HUGETLB_PAGE_ORDER);
+ nid = (nid + 1) % numnodes;
+ return page;
+}
+
void free_huge_page(struct page *page);

static struct page *alloc_hugetlb_page(void)
@@ -35,13 +67,11 @@ static struct page *alloc_hugetlb_page(v
struct page *page;

spin_lock(&htlbpage_lock);
- if (list_empty(&htlbpage_freelist)) {
+ page = dequeue_huge_page();
+ if (!page) {
spin_unlock(&htlbpage_lock);
return NULL;
}
-
- page = list_entry(htlbpage_freelist.next, struct page, list);
- list_del(&page->list);
htlbpagemem--;
spin_unlock(&htlbpage_lock);
set_page_count(page, 1);
@@ -253,7 +283,7 @@ void free_huge_page(struct page *page)
INIT_LIST_HEAD(&page->list);

spin_lock(&htlbpage_lock);
- list_add(&page->list, &htlbpage_freelist);
+ enqueue_huge_page(page);
htlbpagemem++;
spin_unlock(&htlbpage_lock);
}
@@ -369,7 +399,8 @@ int try_to_free_low(int count)

map = NULL;
spin_lock(&htlbpage_lock);
- list_for_each(p, &htlbpage_freelist) {
+ /* all lowmem is on node 0 */
+ list_for_each(p, &hugepage_freelists[0]) {
if (map) {
list_del(&map->list);
update_and_free_page(map);
@@ -406,11 +437,11 @@ int set_hugetlb_mem_size(int count)
return (int)htlbzone_pages;
if (lcount > 0) { /* Increase the mem size. */
while (lcount--) {
- page = alloc_pages(__GFP_HIGHMEM, HUGETLB_PAGE_ORDER);
+ page = alloc_fresh_huge_page();
if (page == NULL)
break;
spin_lock(&htlbpage_lock);
- list_add(&page->list, &htlbpage_freelist);
+ enqueue_huge_page(page);
htlbpagemem++;
htlbzone_pages++;
spin_unlock(&htlbpage_lock);
@@ -451,12 +482,15 @@ static int __init hugetlb_init(void)
int i;
struct page *page;

+ for (i = 0; i < MAX_NUMNODES; ++i)
+ INIT_LIST_HEAD(&hugepage_freelists[i]);
+
for (i = 0; i < htlbpage_max; ++i) {
- page = alloc_pages(__GFP_HIGHMEM, HUGETLB_PAGE_ORDER);
+ page = alloc_fresh_huge_page();
if (!page)
break;
spin_lock(&htlbpage_lock);
- list_add(&page->list, &htlbpage_freelist);
+ enqueue_huge_page(page);
spin_unlock(&htlbpage_lock);
}
htlbpage_max = htlbpagemem = htlbzone_pages = i;
-
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