Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752652AbcLLM5K (ORCPT ); Mon, 12 Dec 2016 07:57:10 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:49216 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100AbcLLM5J (ORCPT ); Mon, 12 Dec 2016 07:57:09 -0500 Date: Mon, 12 Dec 2016 12:56:48 +0000 From: Russell King - ARM Linux To: Vaneet Narang Cc: Maninder Singh , "nicolas.pitre@linaro.org" , "ssantosh@kernel.org" , "panand@redhat.com" , "arnd@arndb.de" , "chris.brandt@renesas.com" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , PANKAJ MISHRA , Ajeet Kumar Yadav Subject: Re: Re: [PATCH 1/1] arm/module: maximum utilization of module area. Message-ID: <20161212125648.GU14217@n2100.armlinux.org.uk> References: <1481012975-44478-1-git-send-email-maninder1.s@samsung.com> <20161212112230epcms5p6af05aef34f72eab15061a166d18cff00@epcms5p6> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161212112230epcms5p6af05aef34f72eab15061a166d18cff00@epcms5p6> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1396 Lines: 35 On Mon, Dec 12, 2016 at 11:22:30AM +0000, Vaneet Narang wrote: > Hi, > > >A PC24 relocation has a range of +/-32MB. This means that where-ever > >the module is placed, it must be capable of reaching any function > >within the kernel text, which may itself be quite large (eg, 8MB, or > >possibly larger). The module area exists to allow modules to be > >located in an area where PC24 relocations are able to reach all of the > >kernel text on sensibly configured kernels, thereby allowing for > >optimal performance. > > > >If you wish to load large modules, then enable ARM_MODULE_PLTS, which > >will use the less efficient PLT method (which is basically an indirect > >function call) for relocations that PC24 can't handle, and will allow > >the module to be loaded into the vmalloc area. > > > >Growing the module area so that smaller modules also get penalised by > >the PLT indirection is not sane. > > This is exactly what i am saying. These changes are useful to accomdate > 22MB modules without enabling ARM_MODULE_PLTS. Obviously I wasn't clear enough. No, I do not like your change for the reasons given above. I'm not going to accept it. If you want to use 22MB modules, enable ARM_MODULE_PLTS. Thank you. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.