patch-2.4.21 linux-2.4.21/mm/highmem.c

• Lines: 46
• Date: 2003-06-13 07:51:39.000000000 -0700
• Orig file: linux-2.4.20/mm/highmem.c
• Orig date: 2002-11-28 15:53:15.000000000 -0800

diff -urN linux-2.4.20/mm/highmem.c linux-2.4.21/mm/highmem.c
@@ -77,7 +77,7 @@
 	flush_tlb_all();
 }
 
-static inline unsigned long map_new_virtual(struct page *page)
+static inline unsigned long map_new_virtual(struct page *page, int nonblocking)
 {
 	unsigned long vaddr;
 	int count;
@@ -96,6 +96,9 @@
 		if (--count)
 			continue;
 
+		if (nonblocking)
+			return 0;
+
 		/*
 		 * Sleep for somebody else to unmap their entries
 		 */
@@ -126,7 +129,7 @@
 	return vaddr;
 }
 
-void *kmap_high(struct page *page)
+void *kmap_high(struct page *page, int nonblocking)
 {
 	unsigned long vaddr;
 
@@ -138,11 +141,15 @@
 	 */
 	spin_lock(&kmap_lock);
 	vaddr = (unsigned long) page->virtual;
-	if (!vaddr)
-		vaddr = map_new_virtual(page);
+	if (!vaddr) {
+		vaddr = map_new_virtual(page, nonblocking);
+		if (!vaddr)
+			goto out;
+	}
 	pkmap_count[PKMAP_NR(vaddr)]++;
 	if (pkmap_count[PKMAP_NR(vaddr)] < 2)
 		BUG();
+ out:
 	spin_unlock(&kmap_lock);
 	return (void*) vaddr;
 }