From owner-freebsd-net@FreeBSD.ORG Thu Jan 15 01:40:03 2009 Return-Path: Delivered-To: freebsd-net@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 593901065672 for ; Thu, 15 Jan 2009 01:40:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 463188FC16 for ; Thu, 15 Jan 2009 01:40:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.3/8.14.3) with ESMTP id n0F1e2fu039596 for ; Thu, 15 Jan 2009 01:40:03 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.3/8.14.3/Submit) id n0F1e2Pe039595; Thu, 15 Jan 2009 01:40:02 GMT (envelope-from gnats) Date: Thu, 15 Jan 2009 01:40:02 GMT Message-Id: <200901150140.n0F1e2Pe039595@freefall.freebsd.org> To: freebsd-net@FreeBSD.org From: Tom Judge Cc: Subject: Re: kern/96268: [socket] TCP socket performance drops by 3000% if packets are split at the first byte X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Tom Judge List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jan 2009 01:40:03 -0000 The following reply was made to PR kern/96268; it has been noted by GNATS. From: Tom Judge To: bug-followup@FreeBSD.org, jost2345@users.sourceforge.net Cc: Subject: Re: kern/96268: [socket] TCP socket performance drops by 3000% if packets are split at the first byte Date: Wed, 14 Jan 2009 19:31:11 -0600 I have seen this issue on 7.0-RELEASE. It seems to be related to the nagle algorithm being enable by default on connections on the loop back interface. One application level work around is to set the TCP_NODELAY option on the socket so that the nagle algorithem is disabled. This bug affects users of php java bridge as newer release talk to a JVM over a tcp socket bound to localhost, and the typical packets passing back and forward are very small. It is also possible to reproduce this bug using PHP 5. I can attach test scripts if required. Tom