Changeset 2220

Timestamp:

May 24, 2011 11:12:36 PM (2 years ago)

Author:

wmb

Message:

TCP - Reduced the TCP receive buffer size to keep the advertised window smaller, thus preventing the other end from sending-ahead more data than small-buffer network interfaces can handle. This makes HTTP reads work much better on OLPC XO-1.5 and 1.75 systems, especially over WLAN.

File:

• ofw/inet/tcp.fth (modified) (1 diff)

ofw/inet/tcp.fth

@@ -1956 +1956 @@
 : alloc-buffers  ( -- )
    wbuf-allocate
-   d# 1024 d# 16 *  to rbuf-len
+   \ If rbuf-len is too large, the other end can send-ahead more data
+   \ than some network interfaces can handle, leading to very poor
+   \ performance and in some cases complete failure.  Ideally we would
+   \ size this dynamically based on the network interface characteristics
+   \ (speed, buffering), but for now we don't have suitable information
+   \ in the network interface device node.
+   d# 1024 8 *  to rbuf-len
    rbuf-len alloc-mem to rbuf-adr
    0 to rbuf-actual