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-rw-r--r--mm/page_alloc.c63
1 files changed, 47 insertions, 16 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5e92698e539..cfd565dbe12 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1380,16 +1380,11 @@ void split_page(struct page *page, unsigned int order)
}
/*
- * Similar to split_page except the page is already free. As this is only
- * being used for migration, the migratetype of the block also changes.
- * As this is called with interrupts disabled, the caller is responsible
- * for calling arch_alloc_page() and kernel_map_page() after interrupts
- * are enabled.
- *
- * Note: this is probably too low level an operation for use in drivers.
- * Please consult with lkml before using this in your driver.
+ * Similar to the split_page family of functions except that the page
+ * required at the given order and being isolated now to prevent races
+ * with parallel allocators
*/
-int split_free_page(struct page *page)
+int capture_free_page(struct page *page, int alloc_order, int migratetype)
{
unsigned int order;
unsigned long watermark;
@@ -1411,10 +1406,11 @@ int split_free_page(struct page *page)
rmv_page_order(page);
__mod_zone_page_state(zone, NR_FREE_PAGES, -(1UL << order));
- /* Split into individual pages */
- set_page_refcounted(page);
- split_page(page, order);
+ if (alloc_order != order)
+ expand(zone, page, alloc_order, order,
+ &zone->free_area[order], migratetype);
+ /* Set the pageblock if the captured page is at least a pageblock */
if (order >= pageblock_order - 1) {
struct page *endpage = page + (1 << order) - 1;
for (; page < endpage; page += pageblock_nr_pages) {
@@ -1425,7 +1421,35 @@ int split_free_page(struct page *page)
}
}
- return 1 << order;
+ return 1UL << order;
+}
+
+/*
+ * Similar to split_page except the page is already free. As this is only
+ * being used for migration, the migratetype of the block also changes.
+ * As this is called with interrupts disabled, the caller is responsible
+ * for calling arch_alloc_page() and kernel_map_page() after interrupts
+ * are enabled.
+ *
+ * Note: this is probably too low level an operation for use in drivers.
+ * Please consult with lkml before using this in your driver.
+ */
+int split_free_page(struct page *page)
+{
+ unsigned int order;
+ int nr_pages;
+
+ BUG_ON(!PageBuddy(page));
+ order = page_order(page);
+
+ nr_pages = capture_free_page(page, order, 0);
+ if (!nr_pages)
+ return 0;
+
+ /* Split into individual pages */
+ set_page_refcounted(page);
+ split_page(page, order);
+ return nr_pages;
}
/*
@@ -2105,7 +2129,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
bool *contended_compaction, bool *deferred_compaction,
unsigned long *did_some_progress)
{
- struct page *page;
+ struct page *page = NULL;
if (!order)
return NULL;
@@ -2118,10 +2142,16 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
current->flags |= PF_MEMALLOC;
*did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
nodemask, sync_migration,
- contended_compaction);
+ contended_compaction, &page);
current->flags &= ~PF_MEMALLOC;
- if (*did_some_progress != COMPACT_SKIPPED) {
+ /* If compaction captured a page, prep and use it */
+ if (page) {
+ prep_new_page(page, order, gfp_mask);
+ goto got_page;
+ }
+
+ if (*did_some_progress != COMPACT_SKIPPED) {
/* Page migration frees to the PCP lists but we want merging */
drain_pages(get_cpu());
put_cpu();
@@ -2131,6 +2161,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
alloc_flags & ~ALLOC_NO_WATERMARKS,
preferred_zone, migratetype);
if (page) {
+got_page:
preferred_zone->compact_considered = 0;
preferred_zone->compact_defer_shift = 0;
if (order >= preferred_zone->compact_order_failed)