From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753975Ab3BEKSS (ORCPT ); Tue, 5 Feb 2013 05:18:18 -0500 Received: from www.linutronix.de ([62.245.132.108]:48371 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751078Ab3BEKSO (ORCPT ); Tue, 5 Feb 2013 05:18:14 -0500 Date: Tue, 5 Feb 2013 11:18:12 +0100 (CET) From: Thomas Gleixner To: Qiang Huang cc: LKML , linux-rt-users , peterz@infradead.org Subject: Re: [ANNOUNCE] 3.6.11-rt26 In-Reply-To: <5110B552.9030903@huawei.com> Message-ID: References: <5110B552.9030903@huawei.com> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 5 Feb 2013, Qiang Huang wrote: > On 2013/2/4 22:58, Thomas Gleixner wrote: > >From patches-3.6.11-rt28.patch.gz, your patch x86-highmem-make-it-work.patch > did this work. And you said > "It had been enabled quite some time, but never really worked." > > But I think there is a previous patch mm-rt-kmap-atomic-scheduling.patch did > the job, so I think RT highmem on x86 should have worked. > > Now with your patch, if we use kmap instead of kmap_atomic on RT, do we need > to revert Peter's patch as well? I should have done that, yes. > I haven't tested it, but if Peter's patch did solved the problem, is his way > better than use kmap? Because we can use more highmem virtual address, > although with some switch latency in some small probability scenarios. In theory it's better. Though I ran into some issues with that approach. It's on my todo list to revisit that problem, but for now the kmap way is at least safer. Thanks, tglx