Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753833Ab3H3FsB (ORCPT ); Fri, 30 Aug 2013 01:48:01 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:60016 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752567Ab3H3Fr7 (ORCPT ); Fri, 30 Aug 2013 01:47:59 -0400 From: Bob Liu To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, hpa@linux.intel.com, yinghai@kernel.org, jacob.shin@amd.com, konrad.wilk@oracle.com, linux-mm@kvack.org, Bob Liu Subject: [PATCH] x86: e820: fix memmap kernel boot parameter Date: Fri, 30 Aug 2013 13:47:53 +0800 Message-Id: <1377841673-17361-1-git-send-email-bob.liu@oracle.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2468 Lines: 64 Kernel boot parameter memmap=nn[KMG]$ss[KMG] is used to mark specific memory as reserved. Region of memory to be used is from ss to ss+nn. But I found the action of this parameter is not as expected. I tried on two machines. Machine1: bootcmdline in grub.cfg "memmap=800M$0x60bfdfff", but the result of "cat /proc/cmdline" changed to "memmap=800M/bin/bashx60bfdfff" after system booted. Machine2: bootcmdline in grub.cfg "memmap=0x77ffffff$0x880000000", the result of "cat /proc/cmdline" changed to "memmap=0x77ffffffx880000000". I didn't find the root cause, I think maybe grub reserved "$0" as something special. Replace '$' with '%' in kernel boot parameter can fix this issue. Signed-off-by: Bob Liu --- Documentation/kernel-parameters.txt | 6 +++--- arch/x86/kernel/e820.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 7f9d4f5..a96c7b1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1604,13 +1604,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. [KNL,ACPI] Mark specific memory as ACPI data. Region of memory to be used, from ss to ss+nn. - memmap=nn[KMG]$ss[KMG] + memmap=nn[KMG]%ss[KMG] [KNL,ACPI] Mark specific memory as reserved. Region of memory to be used, from ss to ss+nn. Example: Exclude memory from 0x18690000-0x1869ffff - memmap=64K$0x18690000 + memmap=64K%0x18690000 or - memmap=0x10000$0x18690000 + memmap=0x10000%0x18690000 memory_corruption_check=0/1 [X86] Some BIOSes seem to corrupt the first 64k of diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index d32abea..8483d45 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -869,7 +869,7 @@ static int __init parse_memmap_one(char *p) } else if (*p == '#') { start_at = memparse(p+1, &p); e820_add_region(start_at, mem_size, E820_ACPI); - } else if (*p == '$') { + } else if (*p == '%') { start_at = memparse(p+1, &p); e820_add_region(start_at, mem_size, E820_RESERVED); } else -- 1.7.10.4 -- 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/