Document the ioengine=net pingpong= option

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 6d541afb412632fdc290b6d5d0b6453b5601be99..b349620107f2dc9935ad07b5cdfda6e0dffc2f73 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1399,6 +1399,15 @@ that defines them is selected.
 [net] listen   For TCP network connections, tell fio to listen for incoming
                connections rather than initiating an outgoing connection. The
                hostname must be omitted if this option is used.
+[net] pingpong Normal a network writer will just continue writing data, and
+               a network reader will just consume packages. If pingpong=1
+               is set, a writer will send its normal payload to the reader,
+               then wait for the reader to send the same payload back. This
+               allows fio to measure network latencies. The submission
+               and completion latencies then measure local time spent
+               sending or receiving, and the completion latency measures
+               how long it took for the other end to receive and send back.
+
 [e4defrag] donorname=str
                File will be used as a block donor(swap extents between files)
 [e4defrag] inplace=int