On Mon, 2015-05-25 at 15:38 -0700, Eric Dumazet wrote: > On Mon, 2015-05-25 at 18:22 -0400, John A. Sullivan III wrote: > > > 2) Why do we still not negotiate the 16MB buffer that we get when we are > > not using GRE? > > What exact NIC handles receive side ? > > If drivers allocate a full 4KB page to hold each frame, > plus sk_buff overhead, > then 32MB of kernel memory translates to 8MB of TCP window space. > > > > Hi, Eric. I'm not sure I understand the question or how to obtain the information you've requested. The receive side system has 48GB of RAM but that does not sound like what you are requesting.
I suspect the behavior is a "protection mechanism", i.e., it is being calculated for good reason. When I set the buffer to 16MB manually in nuttcp, performance degraded so I assume I was overrunning something. I am still downloading the traces. But I'm still mystified by why this only affects GRE traffic. Thanks - John -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
