Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755583AbaA1SWu (ORCPT ); Tue, 28 Jan 2014 13:22:50 -0500 Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:51163 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755299AbaA1SWs (ORCPT ); Tue, 28 Jan 2014 13:22:48 -0500 Date: Tue, 28 Jan 2014 18:22:30 +0000 From: Russell King - ARM Linux To: Santosh Shilimkar Cc: Yinghai Lu , Kevin Hilman , Olof Johansson , Linus Torvalds , Andrew Morton , Ingo Molnar , "H. Peter Anvin" , Dave Hansen , "linux-kernel@vger.kernel.org" , Konrad Rzeszutek Wilk Subject: Re: [PATCH 1/3] memblock, nobootmem: Add memblock_virt_alloc_low() Message-ID: <20140128182230.GO15937@n2100.arm.linux.org.uk> References: <1390590670-25901-1-git-send-email-yinghai@kernel.org> <1390590670-25901-4-git-send-email-yinghai@kernel.org> <52E7E776.30909@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52E7E776.30909@ti.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 28, 2014 at 12:23:02PM -0500, Santosh Shilimkar wrote: > On Tuesday 28 January 2014 12:12 PM, Yinghai Lu wrote: > > Index: linux-2.6/include/linux/bootmem.h > > =================================================================== > > --- linux-2.6.orig/include/linux/bootmem.h > > +++ linux-2.6/include/linux/bootmem.h > > @@ -179,6 +179,9 @@ static inline void * __init memblock_vir > > NUMA_NO_NODE); > > } > > > > +/* Take arch's ARCH_LOW_ADDRESS_LIMIT at first*/ > > +#include > > + > > #ifndef ARCH_LOW_ADDRESS_LIMIT > > #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL > > #endif > > This won't help mostly since the ARM 32 arch don't set ARCH_LOW_ADDRESS_LIMIT. > Sorry i couldn't respond to the thread earlier because of travel and > don't have access to my board to try out the patches. Let's think about this for a moment, shall we... What does memblock_alloc_virt*() return? It returns a virtual address. How is that virtual address obtained? ptr = phys_to_virt(alloc); What is the valid address range for passing into phys_to_virt() ? Only lowmem addresses. Hence, having ARCH_LOW_ADDRESS_LIMIT set to 4GB-1 by default seems to be completely rediculous - and presumably this also fails on x86_32 if it returns memory up at 4GB. So... yes, I think reverting the arch/arm part of this patch is the right solution, whether the rest of it should be reverted is something I can't comment on. -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit". -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/