1 files changed, 25 insertions, 4 deletions

diff --git a/src/mapping.c b/src/mapping.c
index 19d7129..e4ce96c 100644
--- a/src/mapping.c
+++ b/src/mapping.c
@@ -5,13 +5,16 @@
 #include <errno.h>
 #include <unistd.h>
 
+#include <stdio.h>
+
 #include "mapping.h"
 
-int map_file(const char* filename, void **addr, size_t *size)
+static int _map_file(const char* filename, void **addr, size_t *size, int writable)
 {
         struct stat info;
         int error = 0;
         int fd;
+        int flags = writable ? MAP_SHARED : MAP_PRIVATE;
 
         error = stat(filename, &info);
         if (!error) {
@@ -19,12 +22,19 @@ int map_file(const char* filename, void **addr, size_t *size)
                 if (info.st_size > 0) {
                         fd = open(filename, O_RDWR);
                         if (fd >= 0) {
-                                *addr = mmap(NULL, *size, 
-                                             PROT_READ | PROT_WRITE, 
-                                             MAP_PRIVATE,
+                                *addr = mmap(NULL, *size,
+                                             PROT_READ | PROT_WRITE,
+                                             flags,
                                              fd, 0);
                                 if (*addr == MAP_FAILED)
                                         error = -1;
+                else {
+                        /* tell kernel to start getting the pages */
+                        error = madvise(*addr, *size, MADV_SEQUENTIAL | MADV_WILLNEED);
+                        if (error) {
+                                perror("madvise");
+                        }
+                }
                                 close(fd);
                         } else
                                 error = fd;
@@ -33,3 +43,14 @@ int map_file(const char* filename, void **addr, size_t *size)
         }
         return error;
 }
+
+
+int map_file(const char* filename, void **addr, size_t *size)
+{
+        return _map_file(filename, addr, size, 0);
+}
+
+int map_file_rw(const char* filename, void **addr, size_t *size)
+{
+        return _map_file(filename, addr, size, 1);
+}