X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fslob.c;h=de5d5563a46c624c82290f0c6591428d1a4fd1c2;hb=6b0c880dfefecedb9ad353014ed41505c32aca82;hp=d50920ecc02bed44acc1dd3cdc2deed467b6b262;hpb=d638d4990bfb99998420e78e8fd4607bca5cf8d0;p=linux-2.6

diff --git a/mm/slob.c b/mm/slob.c
index d50920ecc0..de5d5563a4 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -293,6 +293,7 @@ static void *slob_page_alloc(struct slob_page *sp, size_t size, int align)
 static void *slob_alloc(size_t size, gfp_t gfp, int align, int node)
 {
 	struct slob_page *sp;
+	struct list_head *prev;
 	slob_t *b = NULL;
 	unsigned long flags;
 
@@ -307,12 +308,22 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node)
 		if (node != -1 && page_to_nid(&sp->page) != node)
 			continue;
 #endif
+		/* Enough room on this page? */
+		if (sp->units < SLOB_UNITS(size))
+			continue;
 
-		if (sp->units >= SLOB_UNITS(size)) {
-			b = slob_page_alloc(sp, size, align);
-			if (b)
-				break;
-		}
+		/* Attempt to alloc */
+		prev = sp->list.prev;
+		b = slob_page_alloc(sp, size, align);
+		if (!b)
+			continue;
+
+		/* Improve fragment distribution and reduce our average
+		 * search time by starting our next search here. (see
+		 * Knuth vol 1, sec 2.5, pg 449) */
+		if (free_slob_pages.next != prev->next)
+			list_move_tail(&free_slob_pages, prev->next);
+		break;
 	}
 	spin_unlock_irqrestore(&slob_lock, flags);
 
@@ -349,7 +360,7 @@ static void slob_free(void *block, int size)
 	slobidx_t units;
 	unsigned long flags;
 
-	if (ZERO_OR_NULL_PTR(block))
+	if (unlikely(ZERO_OR_NULL_PTR(block)))
 		return;
 	BUG_ON(!size);
 
@@ -455,7 +466,7 @@ void kfree(const void *block)
 {
 	struct slob_page *sp;
 
-	if (ZERO_OR_NULL_PTR(block))
+	if (unlikely(ZERO_OR_NULL_PTR(block)))
 		return;
 
 	sp = (struct slob_page *)virt_to_page(block);
@@ -473,7 +484,8 @@ size_t ksize(const void *block)
 {
 	struct slob_page *sp;
 
-	if (ZERO_OR_NULL_PTR(block))
+	BUG_ON(!block);
+	if (unlikely(block == ZERO_SIZE_PTR))
 		return 0;
 
 	sp = (struct slob_page *)virt_to_page(block);