Task #11059: Disable O_DIRECT as it provides abysmal performance on the current CEP4 settings

RTCP/Cobalt/OutputProc/src/MSWriterFile.h

@@ -21,11 +21,32 @@
 #ifndef LOFAR_STORAGE_MSWRITERFILE_H
 #define LOFAR_STORAGE_MSWRITERFILE_H
 
+// O_DIRECT gave us bad performance on CEP4. Compare:
+/*
+
+root@cpu01 ~]# dd if=/dev/zero of=/data/test/throughput.dd bs=104857600 count=10 oflag=direct
+10+0 records in
+10+0 records out
+1048576000 bytes (1.0 GB) copied, 60.8431 s, 17.2 MB/s
+
+[root@cpu01 ~]# dd if=/dev/zero of=/data/test/throughput.dd bs=104857600 count=10
+10+0 records in
+10+0 records out
+1048576000 bytes (1.0 GB) copied, 0.879391 s, 1.2 GB/s
+
+*/
+//#define USE_O_DIRECT
+
+#ifdef USE_O_DIRECT
+#include "FastFileStream.h"
+#else
+#include <Stream/FileStream.h>
+#endif
+
 #include <string>
 
 #include <CoInterface/StreamableData.h>
 #include "MSWriter.h"
-#include "FastFileStream.h"
 
 namespace LOFAR
 {
@@ -49,7 +70,11 @@ namespace LOFAR
       virtual size_t getDataSize();
 
     protected:
+#ifdef USE_O_DIRECT
       FastFileStream itsFile;
+#else
+      FileStream itsFile;
+#endif
     };