added madvise MADV_RANDOM is rrd_update uses mmap

[rrdtool.git] / src / rrd_update.c

diff --git a/src/rrd_update.c b/src/rrd_update.c
index 5f27c2f966a66784e50bf5d1a7193f9177d3095e..608c3146c39b9ff1f9c4954c9e586c81c6715a21 100644 (file)
--- a/src/rrd_update.c
+++ b/src/rrd_update.c
@@ -427,7 +427,12 @@ _rrd_update(const char *filename, const char *tmplt, int argc, const char **argv
         fclose(rrd_file);
        return(-1);
     }
+#ifdef HAVE_MADVISE
+    /* when we use mmaping we tell the kernel the mmap equivalent
+       of POSIX_FADV_RANDOM */
+    madvise(rrd_mmaped_file,rrd_filesize,MADV_RANDOM);
 #endif
+#endif    
     /* loop through the arguments. */
     for(arg_i=0; arg_i<argc;arg_i++) {
        char *stepper = strdup(argv[arg_i]);