Signed-off-by: Andrew Morton <akpm@osdl.org>
Index: linux-2.6.8-rc1/mm/msync.c
===================================================================
--- linux-2.6.8-rc1.orig/mm/msync.c	2004-07-15 02:41:41.000000000 +1000
+++ linux-2.6.8-rc1/mm/msync.c	2004-07-15 10:03:29.655708618 +1000
@@ -92,8 +92,8 @@
 	return error;
 }
 
-static int filemap_sync(struct vm_area_struct * vma, unsigned long address,
-	size_t size, unsigned int flags)
+static int __filemap_sync(struct vm_area_struct *vma, unsigned long address,
+			size_t size, unsigned int flags)
 {
 	pgd_t * dir;
 	unsigned long end = address + size;
@@ -131,6 +131,30 @@
 	return error;
 }
 
+#ifdef CONFIG_PREEMPT
+static int filemap_sync(struct vm_area_struct *vma, unsigned long address,
+			size_t size, unsigned int flags)
+{
+	const size_t chunk = 64 * 1024;	/* bytes */
+	int error = 0;
+
+	while (size) {
+		size_t sz = min(size, chunk);
+
+		error |= __filemap_sync(vma, address, sz, flags);
+		address += sz;
+		size -= sz;
+	}
+	return error;
+}
+#else
+static int filemap_sync(struct vm_area_struct *vma, unsigned long address,
+			size_t size, unsigned int flags)
+{
+	return __filemap_sync(vma, address, size, flags);
+}
+#endif
+
 /*
  * MS_SYNC syncs the entire file - including mappings.
  *