From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 30 May 2002 05:11:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 30 May 2002 05:11:20 -0400 Received: from h-64-105-136-78.SNVACAID.covad.net ([64.105.136.78]:3764 "EHLO freya.yggdrasil.com") by vger.kernel.org with ESMTP id ; Thu, 30 May 2002 05:11:20 -0400 From: "Adam J. Richter" Date: Thu, 30 May 2002 02:11:12 -0700 Message-Id: <200205300911.CAA01655@adam.yggdrasil.com> To: linux-kernel@vger.kernel.org Subject: Does pci_alloc_consisent really need to zero memory? Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Is it really necessary for pci_alloc_consistent() to fill the memory that it returns with all zeroes? I don't see anything in Documentation/DMA-mapping.txt that specifies it. I have been on the lookout for drivers that rely on it for the past couple of months, and I haven't seen any. It's only one line of code in arch/i386/kernel/pci-dma.c, but it is potentially a lot of cycles, even if only zeroes the space you requested (rather than the full pages that it actually allocates). If nobody objects in the next half day or so (or asks me to follow some other course of action), I'll submit a patch for 2.5 for all architectures. Adam J. Richter __ ______________ 575 Oroville Road adam@yggdrasil.com \ / Milpitas, California 95035 +1 408 309-6081 | g g d r a s i l United States of America "Free Software For The Rest Of Us."