mm: add alloc_pages_exact_nid()

Add a alloc_pages_exact_nid() that allocates on a specific node.

The naming is quite broken, but fixing that would need a larger renaming
action.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index bfb8f934521e02b313cc1a497ec08850ac3493c1..56d8fc87fbbc70e8f1d5de07aa0bd7aaccd6887c 100644 (file)
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -353,6 +353,8 @@ extern unsigned long get_zeroed_page(gfp_t gfp_mask);
 
 void *alloc_pages_exact(size_t size, gfp_t gfp_mask);
 void free_pages_exact(void *virt, size_t size);
+/* This is different from alloc_pages_exact_node !!! */
+void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask);
 
 #define __get_free_page(gfp_mask) \
                __get_free_pages((gfp_mask), 0)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 454191a251735a6e0aeefc0ae1d705065a198f95..570d944daeb5d9cd0593c68b57698b2019acfdc9 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2317,6 +2317,21 @@ void free_pages(unsigned long addr, unsigned int order)
 
 EXPORT_SYMBOL(free_pages);
 
+static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size)
+{
+       if (addr) {
+               unsigned long alloc_end = addr + (PAGE_SIZE << order);
+               unsigned long used = addr + PAGE_ALIGN(size);
+
+               split_page(virt_to_page((void *)addr), order);
+               while (used < alloc_end) {
+                       free_page(used);
+                       used += PAGE_SIZE;
+               }
+       }
+       return (void *)addr;
+}
+
 /**
  * alloc_pages_exact - allocate an exact number physically-contiguous pages.
  * @size: the number of bytes to allocate
@@ -2336,21 +2351,31 @@ void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
        unsigned long addr;
 
        addr = __get_free_pages(gfp_mask, order);
-       if (addr) {
-               unsigned long alloc_end = addr + (PAGE_SIZE << order);
-               unsigned long used = addr + PAGE_ALIGN(size);
-
-               split_page(virt_to_page((void *)addr), order);
-               while (used < alloc_end) {
-                       free_page(used);
-                       used += PAGE_SIZE;
-               }
-       }
-
-       return (void *)addr;
+       return make_alloc_exact(addr, order, size);
 }
 EXPORT_SYMBOL(alloc_pages_exact);
 
+/**
+ * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
+ *                        pages on a node.
+ * @size: the number of bytes to allocate
+ * @gfp_mask: GFP flags for the allocation
+ *
+ * Like alloc_pages_exact(), but try to allocate on node nid first before falling
+ * back.
+ * Note this is not alloc_pages_exact_node() which allocates on a specific node,
+ * but is not exact.
+ */
+void *alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
+{
+       unsigned order = get_order(size);
+       struct page *p = alloc_pages_node(nid, gfp_mask, order);
+       if (!p)
+               return NULL;
+       return make_alloc_exact((unsigned long)page_address(p), order, size);
+}
+EXPORT_SYMBOL(alloc_pages_exact_nid);
+
 /**
  * free_pages_exact - release memory allocated via alloc_pages_exact()
  * @virt: the value returned by alloc_pages_exact.