Author: wmb Date: Tue May 24 23:12:36 2011 New Revision: 2220 URL: http://tracker.coreboot.org/trac/openfirmware/changeset/2220
Log: 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.
Modified: ofw/inet/tcp.fth
Modified: ofw/inet/tcp.fth ============================================================================== --- ofw/inet/tcp.fth Mon May 23 23:06:42 2011 (r2219) +++ ofw/inet/tcp.fth Tue May 24 23:12:36 2011 (r2220) @@ -1955,7 +1955,13 @@ \ This is basically attach : 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