X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Frrd_open.c;h=3740750fb73e6839ead4d5c7a13a54e02547ad1c;hb=36b14cdfdbba7713d65c4d416b27c94b495b154a;hp=08c798482e94eb4349cd183ad2add4b3f7b2c9f7;hpb=4af79d1fe0fbb9655cf28a0989d2e98b94b37460;p=rrdtool.git

diff --git a/src/rrd_open.c b/src/rrd_open.c
index 08c7984..3740750 100644
--- a/src/rrd_open.c
+++ b/src/rrd_open.c
@@ -87,6 +87,19 @@ rrd_open(const char *file_name, FILE **in_file, rrd_t *rrd, int rdwr)
         rrd_set_error("opening '%s': %s",file_name, rrd_strerror(errno));
         return (-1);
     }
+
+#ifdef HAVE_POSIX_FADVISE
+    /* In general we need no read-ahead when dealing with rrd_files.
+       When we stop reading, it is highly unlikely that we start up again.
+       In this manner we actually save time and diskaccess (and buffer cache).
+       Thanks to Dave Plonka for the Idea of using POSIX_FADV_RANDOM here. */       
+    if (0 != posix_fadvise(fileno(*in_file), 0, 0, POSIX_FADV_RANDOM)) {
+        rrd_set_error("setting POSIX_FADV_RANDOM on '%s': %s",file_name, rrd_strerror(errno));
+        fclose(*in_file);
+        return(-1);
+     }    
+#endif
+
 /*
         if (rdwr == RRD_READWRITE)
         {