From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754826AbeDPLGp (ORCPT ); Mon, 16 Apr 2018 07:06:45 -0400 Received: from mail-pg0-f66.google.com ([74.125.83.66]:35297 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754534AbeDPLGn (ORCPT ); Mon, 16 Apr 2018 07:06:43 -0400 X-Google-Smtp-Source: AIpwx48JlooSFaV/Vk/QEdClcv8XjeN12XBnRx+j5C03t8lkLzutTrqEDd5swIRFbIH778DbUdlg9A== Message-ID: <5AD483BD.70804@gmail.com> Date: Mon, 16 Apr 2018 19:06:37 +0800 From: zoucao-ipc User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: zoucao@linux.alibaba.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com CC: x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86/boot/e820: add new chareater "-" to free BIOS memory in memmap bootargs References: <20180410025912.49830-1-zoucao@linux.alibaba.com> <20180410025912.49830-2-zoucao@linux.alibaba.com> In-Reply-To: <20180410025912.49830-2-zoucao@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org any suggestions？ On 2018/4/10 上午10:59, zoucao@linux.alibaba.com wrote: > From: zoucao > > Normally every BIOS reserved memory is used for some features, we can't > use them, but in some conditions, users can ensure some BIOS memories > are not used and reserved memory is well to free, they have not a good > way to free these memories, here add a new chareater "-" in memmap to > free reserved memory. > > Signed-off-by: zou cao > --- > 7u/Documentation/kernel-parameters.txt | 6 ++++++ > 7u/arch/x86/kernel/e820.c | 3 +++ > 2 files changed, 9 insertions(+) > > diff --git a/7u/Documentation/kernel-parameters.txt b/7u/Documentation/kernel-parameters.txt > index 9a1abb99a..dbea75e12 100644 > --- a/7u/Documentation/kernel-parameters.txt > +++ b/7u/Documentation/kernel-parameters.txt > @@ -1677,6 +1677,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > or > memmap=0x10000$0x18690000 > > + memmap=nn[KMG]-ss[KMG] > + Free E820 reserved memory, as specified by the user. > + Region of reserved memory to be free, from ss to ss+nn. > + Example: free reserved memory from 0x18690000-0x186a0000 > + memmap=0x4101000-0x6aeff000 > + > memory_corruption_check=0/1 [X86] > Some BIOSes seem to corrupt the first 64k of > memory when doing things like suspend/resume. > diff --git a/7u/arch/x86/kernel/e820.c b/7u/arch/x86/kernel/e820.c > index 174da5fc5..b8a042981 100644 > --- a/7u/arch/x86/kernel/e820.c > +++ b/7u/arch/x86/kernel/e820.c > @@ -875,6 +875,9 @@ static int __init parse_memmap_one(char *p) > } else if (*p == '$') { > start_at = memparse(p+1, &p); > e820_add_region(start_at, mem_size, E820_RESERVED); > + } else if (*p == '-') { > + start_at = memparse(p+1, &p); > + e820_remove_range(start_at, mem_size, E820_RESERVED, E820_RAM); > } else > e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); >