Just out of curiosity was the window size changed in 2.6.15? Just trying to get an idea of what might have changed in 2.6.15 that triggered this. (In 2.6.14 and 2.4.27 things run very fast)
On 3/9/06, Stephen Hemminger <[EMAIL PROTECTED]> wrote: > On Wed, 08 Mar 2006 23:29:48 -0800 (PST) > "David S. Miller" <[EMAIL PROTECTED]> wrote: > > > From: Stephen Hemminger <[EMAIL PROTECTED]> > > Date: Wed, 08 Mar 2006 23:24:22 -0800 > > > > > I have gotten massive strace's and the java VM is: > > > 1) Turning on TCP_NODELAY > > > 2) Sending small packets. > > > > Java is doing the wrong thing, obviously. > > > > > 4) Fix java > > > > And this is the only reasonable recourse. > > > > You cannot turn on TCP_NODELAY and expect good performance > > when sending out small packets. You are asking for low > > latency and no delaying of packets in order to allow larger > > ones to accumulate. > > > > The kernel is doing exactly what Java is asking it to do. > > > > In fact I consider the new behavior of the kernel a bug fix. > > A possible solution would be to set cwnd bigger for loopback. > If there was a clean way to know that connection was over loopback, > then doing something in tcp_init_metrics() to set INIT_CWND > > if (IsLoopback(sk)) > dst->metrics[RTAX_INIT_CWND-1] = 10; > then tcp_init_cwnd() would return a bigger congestion window. > - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
