Re: smaller blocksizes with solaris
Oops did not realize it was the same person. Doh... Sorry.
Also since I went to look at it now, the check in Settings.cpp does not
modify the arguement at all. It prints an error but that is AFTER it sets
the setting variable. I just stepped through the execution and it does in
fact call setsockopt with a value of 16. Therefore Solaris is not giving
the requested size not Iperf doing something wrong. Here is a walk through
on Linux
124 newTCPWin = inTCPWin;
(gdb)
125 rc = setsockopt( inSock, SOL_SOCKET, SO_RCVBUF,
(gdb) print inTCPWin
$1 = 16
(gdb) print newTCPWin
$2 = 16
(gdb) c
Continuing.
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 256 Byte (WARNING: requested 16.0 Byte)
------------------------------------------------------------
As you can see my linux setup only supports a window down to 256 Bytes.
Kevin
On Mon, 12 Apr 2004, jesse butler wrote:
> Hi,
>
> As communicated earlier, I'm having some trouble using small blocksizes
> with Iperf. As shown below, I attempt to use 16 bytes, but after the
> warn, it is set to 32 KB.
>
> [jesseb --at-- aion]: ~/iperf/iperf-1.1.1 $ iperf -c aion -w 16
> WARNING: TCP window size set to 16 bytes. A small window size
> will give poor performance. See the Iperf documentation.
> ------------------------------------------------------------
> Client connecting to aion, TCP port 5001
> TCP window size: 32.0 KByte (WARNING: requested 16.0 Byte)
> ------------------------------------------------------------
> [ 4] local 129.148.184.208 port 36483 connected
>
>
> I would like to change the code and rebuild so it will work for me, but
> am a bit stuck. I've discovered that at some point, a small blocksize
> is getting overridden with a larger size, but I can't find where in the
> code. I have traced it into lib/tcp_window_size.c and
> setsock_tcp_windowsize(), which in turn calls setsockopt()... but I
> don't see anywhere where if the window size passed in is overridden if
> it's smaller than a certain size.
>
> Anyone have any ideas, see anything, want to bop me on the head for
> missing something obvious?
>
> Thanks,
> Jesse
>