diff -u --recursive --new-file pre3/linux/arch/i386/kernel/entry.S linux/arch/i386/kernel/entry.S
--- pre3/linux/arch/i386/kernel/entry.S	Mon Oct  8 10:39:58 2001
+++ linux/arch/i386/kernel/entry.S	Wed Oct 17 10:02:39 2001
@@ -621,6 +621,7 @@
 	.long SYMBOL_NAME(sys_ni_syscall)	/* reserved for TUX */
 	.long SYMBOL_NAME(sys_ni_syscall)	/* Reserved for Security */
 	.long SYMBOL_NAME(sys_gettid)
+	.long SYMBOL_NAME(sys_readahead)	/* 225 */
 
 	.rept NR_syscalls-(.-sys_call_table)/4
 		.long SYMBOL_NAME(sys_ni_syscall)
diff -u --recursive --new-file pre3/linux/include/asm-i386/unistd.h linux/include/asm-i386/unistd.h
--- pre3/linux/include/asm-i386/unistd.h	Mon Oct  8 10:40:16 2001
+++ linux/include/asm-i386/unistd.h	Wed Oct 17 10:03:03 2001
@@ -229,6 +229,7 @@
 #define __NR_fcntl64		221
 #define __NR_security		223	/* syscall for security modules */
 #define __NR_gettid		224
+#define __NR_readahead		225
 
 /* user-visible error numbers are in the range -1 - -124: see <asm-i386/errno.h> */
 
diff -u --recursive --new-file pre3/linux/mm/filemap.c linux/mm/filemap.c
--- pre3/linux/mm/filemap.c	Mon Oct 15 16:17:40 2001
+++ linux/mm/filemap.c	Wed Oct 17 10:21:37 2001
@@ -1520,6 +1520,53 @@
 	return retval;
 }
 
+static ssize_t do_readahead(struct file *file, unsigned long index, unsigned long nr)
+{
+	struct address_space *mapping = file->f_dentry->d_inode->i_mapping;
+	unsigned long max;
+
+	if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
+		return -EINVAL;
+
+	/* Limit it to the size of the file.. */
+	max = (mapping->host->i_size + ~PAGE_CACHE_MASK) >> PAGE_CACHE_SHIFT;
+	if (index > max)
+		return 0;
+	max -= index;
+	if (nr > max)
+		nr = max;
+
+	/* And limit it to a sane percentage of the inactive list.. */
+	max = nr_inactive_pages / 2;
+	if (nr > max)
+		nr = max;
+
+	while (nr) {
+		page_cache_read(file, index);
+		index++;
+		nr--;
+	}
+	return 0;
+}
+
+asmlinkage ssize_t sys_readahead(int fd, loff_t offset, size_t count)
+{
+	ssize_t ret;
+	struct file *file;
+
+	ret = -EBADF;
+	file = fget(fd);
+	if (file) {
+		if (file->f_mode & FMODE_READ) {
+			unsigned long start = offset >> PAGE_CACHE_SHIFT;
+			unsigned long len = (count + ((long)offset & ~PAGE_CACHE_MASK)) >> PAGE_CACHE_SHIFT;
+			ret = do_readahead(file, start, len);
+		}
+		fput(file);
+	}
+	return ret;
+}
+
 /*
  * Read-ahead and flush behind for MADV_SEQUENTIAL areas.  Since we are
  * sure this is sequential access, we don't need a flexible read-ahead