From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755360Ab1JQNb2 (ORCPT ); Mon, 17 Oct 2011 09:31:28 -0400 Received: from enyo.dsw2k3.info ([195.71.86.239]:45560 "EHLO enyo.dsw2k3.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754892Ab1JQNbY (ORCPT ); Mon, 17 Oct 2011 09:31:24 -0400 X-Greylist: delayed 474 seconds by postgrey-1.27 at vger.kernel.org; Mon, 17 Oct 2011 09:31:24 EDT Date: Mon, 17 Oct 2011 15:23:18 +0200 From: Matthias Schniedermeyer To: Charles Buysschaert Cc: "linux-kernel@vger.kernel.org" Subject: Re: Speed of RAM reserved with memmap kernel command line option. Message-ID: <20111017132318.GA9098@citd.de> References: <894F5F1132E3C5458AAB08FA0A1AC9380F1E2F12@IPX-MAIL.Intopix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <894F5F1132E3C5458AAB08FA0A1AC9380F1E2F12@IPX-MAIL.Intopix.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17.10.2011 07:51, Charles Buysschaert wrote: > Hello all, > > We are writing a PCI-e "frame grabber-like" driver for linux 2.6 kernel. ... > I guess cache is not used. Does anyone know if there is a way to speed this up? How could we set that area to "cached"? Smells to me like you are missing a mapping in MTRR ... Documentation/x86/mtrr.txt ... or PAT. Documentation/x86/pat.txt Bis denn -- Real Programmers consider "what you see is what you get" to be just as bad a concept in Text Editors as it is in women. No, the Real Programmer wants a "you asked for it, you got it" text editor -- complicated, cryptic, powerful, unforgiving, dangerous.