From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] ARCH OMAP : enable ARCH_HAS_HOLES_MEMORYMODEL for OMAP Date: Mon, 11 Jan 2010 15:06:12 -0800 Message-ID: <20100111230612.GD5055@atomide.com> References: <1262867408-9895-1-git-send-email-srk@ti.com> <4B45FC4B.9080302@ti.com> <4B47491F.1000303@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-ewr.mailhop.org ([204.13.248.71]:64518 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751476Ab0AKXGH (ORCPT ); Mon, 11 Jan 2010 18:06:07 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Govindarajan, Sriramakrishnan" Cc: "Menon, Nishanth" , "linux-omap@vger.kernel.org" , "Syed Mohammed, Khasim" , "Nori, Sekhar" * Govindarajan, Sriramakrishnan [100111 04:11]: > From: Menon, Nishanth > > Sent: Friday, January 08, 2010 8:33 PM > > To: Govindarajan, Sriramakrishnan > > Cc: linux-omap@vger.kernel.org; Syed Mohammed, Khasim; Nori, Sekhar > > Subject: Re: [PATCH] ARCH OMAP : enable ARCH_HAS_HOLES_MEMORYMODEL for > > OMAP > > > > Govindarajan, Sriramakrishnan had written, on 01/08/2010 02:15 AM, the > > following: > > > > > >> From: Menon, Nishanth > > >> Govindarajan, Sriramakrishnan had written, on 01/07/2010 06:30 AM, the > > >> following: > > >>> From: Sriram > > >>> > > >>> OMAP platforms(like OMAP3530) include DSP or other co-processors > > >>> for media acceleration. when carving out memory for the > > >>> accelerators we can end up creating a hole in the memory map > > >>> of sort: > > >>> > > >>> > > >>> To handle such a memory configuration ARCH_HAS_HOLES_MEMORYMODEL > > >>> has to be enabled. For further information refer discussion at: > > >>> http://www.mail-archive.com/linux-omap@vger.kernl.org/msg15262.html. > > >> pls check the link: I see "The document you were looking for was not > > >> found." > > > > > > The URL is spelt incorrectly. Here is the correct URL: > > > http://www.mail-archive.com/linux-omap@vger.kernel.org/msg15262.html > > > > > >>> select GENERIC_TIME > > >>> select GENERIC_CLOCKEVENTS > > >>> + select ARCH_HAS_HOLES_MEMORYMODEL > > >> why enable this for all OMAPs? > > > > > > I have tested this on several OMAP3 platforms and this feature is > > required > > > Wherever some memory needs to be reserved for media accelerators - hence > > it > > > Would be handy for earlier OMAP platforms as well > > I understand that you have tested with OMAP3. my question is you have > > handled this as per the diff > > @@ -699,6 +699,7 @@ config ARCH_OMAP > > to ARCH_OMAP > > > > is this good for OMAP1510, 1610, 1710, 2420,2430, 770 etc..? > > I do not have other OMAP platforms for me to validate this patch on. > I believe the nature of change is generic and benefit other OMAP > Platforms as well. Sounds like the issue is a slight performance penalty when not used. But considering all the coprocessors, I'd say let's apply this so the checks are in place when using the coprocessors. Regards, Tony