From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v3 02/31] arm64: Kernel booting and initialisation Date: Mon, 10 Sep 2012 14:48:20 +0000 Message-ID: <201209101448.20745.arnd@arndb.de> References: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> <201209101353.34325.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Nicolas Pitre Cc: "linux-arch@vger.kernel.org" , Catalin Marinas , Jean-Christophe PLAGNIOL-VILLARD , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: linux-arch.vger.kernel.org On Monday 10 September 2012, Nicolas Pitre wrote: > On Mon, 10 Sep 2012, Arnd Bergmann wrote: > > On Monday 10 September 2012, Catalin Marinas wrote: > > > On Mon, Sep 10, 2012 at 06:53:39AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote: > > I think a bunch of other architectures can have relocatable kernels, which > > is useful e.g. for kdump. It does imply a small runtime cost and may have > > other disadvantages though. > > Relocatable in physical space is what kdump actually needs, and that's > what we already have here (as well as on ARM32 for that matter with > CONFIG_ARM_PATCH_PHYS_VIRT). Relocatable in the virtual space is costly > and we shouldn't need to go there. Ah, I see. I thought that the other architectures (powerpc and x86) doing this were actually building with -fPIC, but they do the same kind of early patching that we do. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from moutng.kundenserver.de ([212.227.17.8]:57578 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753100Ab2IJOu6 (ORCPT ); Mon, 10 Sep 2012 10:50:58 -0400 From: Arnd Bergmann Subject: Re: [PATCH v3 02/31] arm64: Kernel booting and initialisation Date: Mon, 10 Sep 2012 14:48:20 +0000 References: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> <201209101353.34325.arnd@arndb.de> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-ID: <201209101448.20745.arnd@arndb.de> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Nicolas Pitre Cc: Catalin Marinas , Jean-Christophe PLAGNIOL-VILLARD , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Message-ID: <20120910144820.ICBE5mC-cbLhWVTLRay4aBFQpkxnT7pTtyvVAyONkSE@z> On Monday 10 September 2012, Nicolas Pitre wrote: > On Mon, 10 Sep 2012, Arnd Bergmann wrote: > > On Monday 10 September 2012, Catalin Marinas wrote: > > > On Mon, Sep 10, 2012 at 06:53:39AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote: > > I think a bunch of other architectures can have relocatable kernels, which > > is useful e.g. for kdump. It does imply a small runtime cost and may have > > other disadvantages though. > > Relocatable in physical space is what kdump actually needs, and that's > what we already have here (as well as on ARM32 for that matter with > CONFIG_ARM_PATCH_PHYS_VIRT). Relocatable in the virtual space is costly > and we shouldn't need to go there. Ah, I see. I thought that the other architectures (powerpc and x86) doing this were actually building with -fPIC, but they do the same kind of early patching that we do. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Mon, 10 Sep 2012 14:48:20 +0000 Subject: [PATCH v3 02/31] arm64: Kernel booting and initialisation In-Reply-To: References: <1347035226-18649-1-git-send-email-catalin.marinas@arm.com> <201209101353.34325.arnd@arndb.de> Message-ID: <201209101448.20745.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 10 September 2012, Nicolas Pitre wrote: > On Mon, 10 Sep 2012, Arnd Bergmann wrote: > > On Monday 10 September 2012, Catalin Marinas wrote: > > > On Mon, Sep 10, 2012 at 06:53:39AM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote: > > I think a bunch of other architectures can have relocatable kernels, which > > is useful e.g. for kdump. It does imply a small runtime cost and may have > > other disadvantages though. > > Relocatable in physical space is what kdump actually needs, and that's > what we already have here (as well as on ARM32 for that matter with > CONFIG_ARM_PATCH_PHYS_VIRT). Relocatable in the virtual space is costly > and we shouldn't need to go there. Ah, I see. I thought that the other architectures (powerpc and x86) doing this were actually building with -fPIC, but they do the same kind of early patching that we do. Arnd