From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx158.postini.com [74.125.245.158]) by kanga.kvack.org (Postfix) with SMTP id 20D3E6B005A for ; Thu, 28 Jun 2012 02:26:03 -0400 (EDT) Received: by qabg27 with SMTP id g27so3159677qab.14 for ; Wed, 27 Jun 2012 23:26:02 -0700 (PDT) Date: Thu, 28 Jun 2012 02:25:59 -0400 (EDT) From: Nicolas Pitre Subject: RE: [PATCH] [RESEND] arm: limit memblock base address for early_pte_alloc In-Reply-To: <00e801cd54f0$eb8a3540$c29e9fc0$@lge.com> Message-ID: References: <1338880312-17561-1-git-send-email-minchan@kernel.org> <025701cd457e$d5065410$7f12fc30$@lge.com> <20120627160220.GA2310@linaro.org> <00e801cd54f0$eb8a3540$c29e9fc0$@lge.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: "Kim, Jong-Sung" Cc: 'Dave Martin' , 'Minchan Kim' , 'Russell King' , 'Catalin Marinas' , 'Chanho Min' , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org On Thu, 28 Jun 2012, Kim, Jong-Sung wrote: > > From: Dave Martin [mailto:dave.martin@linaro.org] > > Sent: Thursday, June 28, 2012 1:02 AM > > > > For me, it appears that this block just contains the initial region passed > > in ATAG_MEM or on the command line, with some reservations for > > swapper_pg_dir, the kernel text/data, device tree and initramfs. > > > > So far as I can tell, the only memory guaranteed to be mapped here is the > > kernel image: there may be no guarantee that there is any unused space in > > this region which could be used to allocate extra page tables. > > The rest appears during the execution of map_lowmem(). > > > > Cheers > > ---Dave > > Thank you for your comment, Dave! It was not that sophisticated choice, but > I thought that normal embedded system trying to reduce the BOM would have a > big-enough first memblock memory region. However you're right. There can be > exceptional systems. Then, how do you think about following manner: [...] This still has some possibilities for failure. Please have a look at the two patches I've posted to fix this in a better way. Nicolas -- 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