Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262319AbVD1Wsx (ORCPT ); Thu, 28 Apr 2005 18:48:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262320AbVD1Wsx (ORCPT ); Thu, 28 Apr 2005 18:48:53 -0400 Received: from gate.crashing.org ([63.228.1.57]:20971 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S262319AbVD1Wss (ORCPT ); Thu, 28 Apr 2005 18:48:48 -0400 Subject: Re: pci-sysfs resource mmap broken (and PATCH) From: Benjamin Herrenschmidt To: Grant Grundler Cc: "David S. Miller" , linux-pci@atrey.karlin.mff.cuni.cz, Linux Kernel list , Greg KH , bjorn.helgaas@hp.com, "David S. Miller" In-Reply-To: <20050428151117.GB10171@colo.lackof.org> References: <1114493609.7183.55.camel@gaston> <20050426163042.GE2612@colo.lackof.org> <1114555655.7183.81.camel@gaston> <1114643616.7183.183.camel@gaston> <20050428053311.GH21784@colo.lackof.org> <20050427223702.21051afc.davem@davemloft.net> <1114670353.7182.246.camel@gaston> <20050427235056.0bd09a94.davem@davemloft.net> <20050428151117.GB10171@colo.lackof.org> Content-Type: text/plain Date: Fri, 29 Apr 2005 08:47:27 +1000 Message-Id: <1114728447.7182.262.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1196 Lines: 28 On Thu, 2005-04-28 at 09:11 -0600, Grant Grundler wrote: > > > Anyways, what I'm trying to say is that blinding turning prefetchable > > BAR into "don't set side effect bit in PTE" might not be so wise. > > > > I really think it's a userlevel decision. That's where all the ioctl() > > garbage came from for the /proc/bus/pci mmap() stuff. It was for chossing > > IO vs MEM space, and also for setting these kinds of mapping attributes. > > Well, if it's a device driver decision, I guess that's ok. > And the primary device driver happens to live in user space in X.org case. Agreed, but 1) Do you have an idea on how to expose this capability with the sysfs interface ? Adding ioctl's to it would suck big time :) and 2) It's still nice to have a "workaround" for existing X since the performance benefit is significant, but then, it's in arch code, so that's fine (and I could indeed limit it to VGA class devices as David suggests). Ben. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/