[Make-wifi-fast] iperf enhancements in 2.0.8

[Bob (Robert) McMahon]

Sure, will do.  I'll apply the below diff, test it, and then commit.  Thanks for the diff.

Bob

-----Original Message-----
From: toke at toke.dk [mailto:toke at toke.dk] 
Sent: Friday, October 16, 2015 1:53 AM
To: Bob (Robert) McMahon
Cc: make-wifi-fast at lists.bufferbloat.net
Subject: Re: [Make-wifi-fast] iperf enhancements in 2.0.8

"Bob (Robert) McMahon" <rmcmahon at broadcom.com> writes:

> Just an FYI for those who might be interested. We added RTT and CWND
> samples in iperf 2.0.8 for the TCP transmitter (iperf client) as well
> as UDP mean/min/max/stdev in the iperf server (assumes the clocks are
> synched.) Also, much faster sampling is supported. These may be
> helpful to those trying to improve wi-fi performance. To get the
> output one needs to use the –e option. Also, RTT/CWND is linux only.
> Apple is evaluating the change set and *may* ship it with future
> phones and Mac OS X systems.

Hi Bob

Any chance of getting the below patch into Iperf? Or in general, getting
sub-second resolution on the timestamps output in CSV mode? Would make
it easier to integrate Iperf into Flent tests (where the timestamps are
used to match the output with other simultaneous test tools).

-Toke

--- a/src/ReportCSV.c	2007-08-29 23:57:27.000000000 +0200
+++ b/src/ReportCSV.c	2012-10-17 15:54:46.516986280 +0200
@@ -149,9 +149,8 @@
 }
 
 void CSV_timestamp( char *timestamp, int length ) {
-    time_t times;
-    struct tm *timest;
-    times = time( NULL );
-    timest = localtime( &times );
-    strftime( timestamp, length,"%Y%m%d%H%M%S", timest );
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    snprintf(timestamp, length, "%lu.%06lu",
+             (unsigned long)tv.tv_sec, (unsigned long)tv.tv_usec);
 }