pktgen: increasing transmission granularity

This patch increases the granularity of the rate generated by pktgen.
The previous version of pktgen uses micro seconds (udelay) resolution when it
was delayed causing gaps in the rates. It is changed to nanosecond (ndelay).
Now any rate is possible.

Also it allows to set, the desired rate in Mb/s or packets per second.

The documentation has been updated.

Signed-off-by: Daniel Turull <daniel.turull@gmail.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt
index 61bb645..75e4fd7 100644
--- a/Documentation/networking/pktgen.txt
+++ b/Documentation/networking/pktgen.txt
@@ -151,6 +151,8 @@
 
  pgset stop    	          aborts injection. Also, ^C aborts generator.
 
+ pgset "rate 300M"        set rate to 300 Mb/s
+ pgset "ratep 1000000"    set rate to 1Mpps
 
 Example scripts
 ===============
@@ -241,6 +243,9 @@
 flows
 flowlen
 
+rate
+ratep
+
 References:
 ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/
 ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/