From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 7 May 2001 19:05:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 7 May 2001 19:05:03 -0400 Received: from pizda.ninka.net ([216.101.162.242]:45994 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Mon, 7 May 2001 19:04:48 -0400 From: "David S. Miller" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15095.10766.342088.612404@pizda.ninka.net> Date: Mon, 7 May 2001 16:04:46 -0700 (PDT) To: Ben LaHaise Cc: Manfred Spraul , Subject: Re: [PATCH] zero^H^H^H^Hsingle copy pipe In-Reply-To: In-Reply-To: <001601c0d713$d60a17b0$5517fea9@local> X-Mailer: VM 6.75 under 21.1 (patch 13) "Crater Lake" XEmacs Lucid Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ben LaHaise writes: > and then use a map_mm_kiobuf (which is > map_user_kiobuf but with an mm parameter) for the portion of the buffer > that's currently being copied. That improves code reuse and gives us a > few primatives that are quite useful elsewhere. If it has roughly the same cost as Manfred's copy_user thing, it is therefore roughly equivalent. If this map_mm_kiobuf() thing would cost more (I think it would because it would be using kiobufs when for this case there is absolutely no need for them) then why? "It's a clean interface everyone can use" is not an acceptable answer when the clean interface costs significantly more than the straightforward approach. Later, David S. Miller davem@redhat.com