From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261834AbULJWGR (ORCPT ); Fri, 10 Dec 2004 17:06:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261835AbULJWGQ (ORCPT ); Fri, 10 Dec 2004 17:06:16 -0500 Received: from clock-tower.bc.nu ([81.2.110.250]:7386 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S261834AbULJWGL (ORCPT ); Fri, 10 Dec 2004 17:06:11 -0500 Subject: Re: SO_RCVLOWAT option to socket() From: Alan Cox To: Rob Sanders Cc: Linux Kernel Mailing List In-Reply-To: References: Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1102712550.3201.70.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Fri, 10 Dec 2004 21:02:32 +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Gwe, 2004-12-10 at 04:06, Rob Sanders wrote: > Hey y'all, > Can anyone point me to a resource for why SO_RCVLOWAT is hardcoded > to 1 in linux? The 1003.1g drafts require it is supported. > If you are using select or poll with timeouts it would be less costly > to have the kernel tell you > when all of the data you reqested (via SO_RCVLOWAT) is ready to be read But is the cost of all those special case checks and all the handling for it such as select computing if enough tcp packets together accumulated worth the cost on every app not using LOWAT for the microscopic gain given that essentially nobody uses it. Alan