From mboxrd@z Thu Jan 1 00:00:00 1970 From: cyril@ti.com (Cyril Chemparathy) Date: Mon, 10 Sep 2012 13:43:23 -0400 Subject: [PATCH v2 16/22] ARM: mm: cleanup checks for membank overlap with vmalloc area In-Reply-To: References: <1344648306-15619-1-git-send-email-cyril@ti.com> <1344648306-15619-17-git-send-email-cyril@ti.com> Message-ID: <504E26BB.4020205@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 8/12/2012 12:36 AM, Nicolas Pitre wrote: > On Fri, 10 Aug 2012, Cyril Chemparathy wrote: > >> On Keystone platforms, physical memory is entirely outside the 32-bit >> addressible range. Therefore, the (bank->start > ULONG_MAX) check below marks >> the entire system memory as highmem, and this causes unpleasentness all over. >> >> This patch eliminates the extra bank start check (against ULONG_MAX) by >> checking bank->start against the physical address corresponding to vmalloc_min >> instead. >> >> In the process, this patch also cleans up parts of the highmem sanity check >> code by removing what has now become a redundant check for banks that entirely >> overlap with the vmalloc range. > > Are you sure of this? The code that you removed not only checks for > banks that fall into the vmalloc area, but it also skipp them. This is > now lost. > I almost missed out on this email... The check is not quite lost, we still have the following in the !CONFIG_HIGHMEM block: if (highmem) { printk(...); continue; } The change is that highmem is now set outside the #ifdef when (bank->start >= vmalloc_limit), and therefore the check is truly redundant. >> Signed-off-by: Cyril Chemparathy >> Signed-off-by: Vitaly Andrianov >> --- >> arch/arm/mm/mmu.c | 19 +------------------ >> 1 file changed, 1 insertion(+), 18 deletions(-) >> >> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c >> index f764c03..3d685c6 100644 >> --- a/arch/arm/mm/mmu.c >> +++ b/arch/arm/mm/mmu.c >> @@ -901,15 +901,12 @@ void __init sanity_check_meminfo(void) >> struct membank *bank = &meminfo.bank[j]; >> *bank = meminfo.bank[i]; >> >> - if (bank->start > ULONG_MAX) >> - highmem = 1; >> - >> -#ifdef CONFIG_HIGHMEM >> if (bank->start >= vmalloc_limit) >> highmem = 1; >> >> bank->highmem = highmem; >> >> +#ifdef CONFIG_HIGHMEM >> /* >> * Split those memory banks which are partially overlapping >> * the vmalloc area greatly simplifying things later. >> @@ -932,8 +929,6 @@ void __init sanity_check_meminfo(void) >> bank->size = vmalloc_limit - bank->start; >> } >> #else >> - bank->highmem = highmem; >> - >> /* >> * Highmem banks not allowed with !CONFIG_HIGHMEM. >> */ >> @@ -946,18 +941,6 @@ void __init sanity_check_meminfo(void) >> } >> >> /* >> - * Check whether this memory bank would entirely overlap >> - * the vmalloc area. >> - */ >> - if (bank->start >= vmalloc_limit) { >> - printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx " >> - "(vmalloc region overlap).\n", >> - (unsigned long long)bank->start, >> - (unsigned long long)bank->start + bank->size - 1); >> - continue; >> - } >> - >> - /* >> * Check whether this memory bank would partially overlap >> * the vmalloc area. >> */ >> -- >> 1.7.9.5 >> -- Thanks - Cyril From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756969Ab2IJRnq (ORCPT ); Mon, 10 Sep 2012 13:43:46 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:40161 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752010Ab2IJRnn (ORCPT ); Mon, 10 Sep 2012 13:43:43 -0400 Message-ID: <504E26BB.4020205@ti.com> Date: Mon, 10 Sep 2012 13:43:23 -0400 From: Cyril Chemparathy User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:15.0) Gecko/20120824 Thunderbird/15.0 MIME-Version: 1.0 To: Nicolas Pitre CC: , , , , , , , Vitaly Andrianov Subject: Re: [PATCH v2 16/22] ARM: mm: cleanup checks for membank overlap with vmalloc area References: <1344648306-15619-1-git-send-email-cyril@ti.com> <1344648306-15619-17-git-send-email-cyril@ti.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/12/2012 12:36 AM, Nicolas Pitre wrote: > On Fri, 10 Aug 2012, Cyril Chemparathy wrote: > >> On Keystone platforms, physical memory is entirely outside the 32-bit >> addressible range. Therefore, the (bank->start > ULONG_MAX) check below marks >> the entire system memory as highmem, and this causes unpleasentness all over. >> >> This patch eliminates the extra bank start check (against ULONG_MAX) by >> checking bank->start against the physical address corresponding to vmalloc_min >> instead. >> >> In the process, this patch also cleans up parts of the highmem sanity check >> code by removing what has now become a redundant check for banks that entirely >> overlap with the vmalloc range. > > Are you sure of this? The code that you removed not only checks for > banks that fall into the vmalloc area, but it also skipp them. This is > now lost. > I almost missed out on this email... The check is not quite lost, we still have the following in the !CONFIG_HIGHMEM block: if (highmem) { printk(...); continue; } The change is that highmem is now set outside the #ifdef when (bank->start >= vmalloc_limit), and therefore the check is truly redundant. >> Signed-off-by: Cyril Chemparathy >> Signed-off-by: Vitaly Andrianov >> --- >> arch/arm/mm/mmu.c | 19 +------------------ >> 1 file changed, 1 insertion(+), 18 deletions(-) >> >> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c >> index f764c03..3d685c6 100644 >> --- a/arch/arm/mm/mmu.c >> +++ b/arch/arm/mm/mmu.c >> @@ -901,15 +901,12 @@ void __init sanity_check_meminfo(void) >> struct membank *bank = &meminfo.bank[j]; >> *bank = meminfo.bank[i]; >> >> - if (bank->start > ULONG_MAX) >> - highmem = 1; >> - >> -#ifdef CONFIG_HIGHMEM >> if (bank->start >= vmalloc_limit) >> highmem = 1; >> >> bank->highmem = highmem; >> >> +#ifdef CONFIG_HIGHMEM >> /* >> * Split those memory banks which are partially overlapping >> * the vmalloc area greatly simplifying things later. >> @@ -932,8 +929,6 @@ void __init sanity_check_meminfo(void) >> bank->size = vmalloc_limit - bank->start; >> } >> #else >> - bank->highmem = highmem; >> - >> /* >> * Highmem banks not allowed with !CONFIG_HIGHMEM. >> */ >> @@ -946,18 +941,6 @@ void __init sanity_check_meminfo(void) >> } >> >> /* >> - * Check whether this memory bank would entirely overlap >> - * the vmalloc area. >> - */ >> - if (bank->start >= vmalloc_limit) { >> - printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx " >> - "(vmalloc region overlap).\n", >> - (unsigned long long)bank->start, >> - (unsigned long long)bank->start + bank->size - 1); >> - continue; >> - } >> - >> - /* >> * Check whether this memory bank would partially overlap >> * the vmalloc area. >> */ >> -- >> 1.7.9.5 >> -- Thanks - Cyril