From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: Arch specific mmap attributes Date: Wed, 07 Apr 2010 18:58:00 +1000 Message-ID: <1270630680.2300.91.camel@pasglop> References: <20100406185246.7E63.A69D9226@jp.fujitsu.com> <1270592111.13812.88.camel@pasglop> <20100407095145.FB70.A69D9226@jp.fujitsu.com> <20100407.000343.181989028.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100407.000343.181989028.davem@davemloft.net> Sender: owner-linux-mm@kvack.org To: David Miller Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org List-Id: linux-arch.vger.kernel.org On Wed, 2010-04-07 at 00:03 -0700, David Miller wrote: > > I'm not against changing kernel internal. I only disagree mmu > > attribute fashion will be become used widely. > > Desktop already uses similar features via PCI mmap > attributes and such, not to mention MSR settings on > x86. This is a very good point, we've had all sort of trouble hacking that in for PCI mmap, between trying to get write combine in, which we got on /proc via a tweak I think we never got over to sysfs, and the ability to control cachability, for which we used to have O_SYNC hacks in /dev/mem, I think there is room for some nice and clean set of attributes here. Cheers, Ben. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org ([63.228.1.57]:48039 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932517Ab0DGI6N (ORCPT ); Wed, 7 Apr 2010 04:58:13 -0400 Subject: Re: Arch specific mmap attributes From: Benjamin Herrenschmidt In-Reply-To: <20100407.000343.181989028.davem@davemloft.net> References: <20100406185246.7E63.A69D9226@jp.fujitsu.com> <1270592111.13812.88.camel@pasglop> <20100407095145.FB70.A69D9226@jp.fujitsu.com> <20100407.000343.181989028.davem@davemloft.net> Content-Type: text/plain; charset="UTF-8" Date: Wed, 07 Apr 2010 18:58:00 +1000 Message-ID: <1270630680.2300.91.camel@pasglop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: David Miller Cc: kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Message-ID: <20100407085800.d9Dfr1Z_440HsVyMRk_mmP6uZge-arTvAg_vG-97FUg@z> On Wed, 2010-04-07 at 00:03 -0700, David Miller wrote: > > I'm not against changing kernel internal. I only disagree mmu > > attribute fashion will be become used widely. > > Desktop already uses similar features via PCI mmap > attributes and such, not to mention MSR settings on > x86. This is a very good point, we've had all sort of trouble hacking that in for PCI mmap, between trying to get write combine in, which we got on /proc via a tweak I think we never got over to sysfs, and the ability to control cachability, for which we used to have O_SYNC hacks in /dev/mem, I think there is room for some nice and clean set of attributes here. Cheers, Ben.