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Date: Thu, 1 Nov 2012 08:49:07 +0000
From: "Zhang, Jun" <jun.zhang@...el.com>
To: "H. Peter Anvin" <hpa@...or.com>
CC: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"x86@...nel.org" <x86@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
"Fleming, Matt" <matt.fleming@...el.com>,
Paul Gortmaker <paul.gortmaker@...driver.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] To crash dump, we need keep other memory type except
E820_RAM, because other type come from BIOS or firmware is used by other
code(for example: PCI_MMCONFIG).
Hello, Anvin
Thank for your advice.
Hello, All
the next patch is made by 2), please review it. Thanks!
Subject: [PATCH] When we are doing a crash dump, we still need non-E820_RAM
memory information in order to do I/O. So only remove all
RAM ranges which need to be dumped.
Signed-off-by: jzha144 <jun.zhang@...el.com>
---
arch/x86/kernel/e820.c | 8 --------
arch/x86/kernel/setup.c | 22 ++++++++++++++++++++++
2 files changed, 22 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index df06ade..0bc1687 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -844,14 +844,6 @@ static int __init parse_memmap_opt(char *p)
return -EINVAL;
if (!strncmp(p, "exactmap", 8)) {
-#ifdef CONFIG_CRASH_DUMP
- /*
- * If we are doing a crash dump, we still need to know
- * the real mem size before original memory map is
- * reset.
- */
- saved_max_pfn = e820_end_of_ram_pfn();
-#endif
e820.nr_map = 0;
userdef = 1;
return 0;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index ca45696..5eb178b 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -480,6 +480,25 @@ static void __init e820_reserve_setup_data(void)
e820_print_map("reserve setup_data");
}
+#ifdef CONFIG_CRASH_DUMP
+static void __init e820_crashdump_remove_ram(void)
+{
+ /*
+ * We are doing a crash dump, so remove all RAM ranges
+ * as they are the ones that need to be dumped.
+ * We still need all non-RAM information in order to do I/O.
+ */
+ /* NOTE: if you use old kexec, please remove memmap=exactmap
+ * which remove all ranges, not only RAM ranges.
+ */
+ saved_max_pfn = e820_end_of_ram_pfn();
+ e820_remove_range(0, ULLONG_MAX, E820_RAM, 1);
+ sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+ printk(KERN_INFO "crash dump non-RAM map:\n");
+ e820_print_map("crash_dump");
+}
+#endif
+
static void __init memblock_x86_reserve_range_setup_data(void)
{
struct setup_data *data;
@@ -751,6 +770,9 @@ void __init setup_arch(char **cmdline_p)
parse_setup_data();
/* update the e820_saved too */
e820_reserve_setup_data();
+#ifdef CONFIG_CRASH_DUMP
+ e820_crashdump_remove_ram();
+#endif
copy_edd();
--
1.7.6
Best Regards!
Jun Zhang
Inet: 8821-4273
Dir.Tel: 86-21-6116-4273
Email: jun.zhang@...el.com
-----Original Message-----
From: H. Peter Anvin [mailto:hpa@...or.com]
Sent: Thursday, November 01, 2012 12:20 PM
To: Zhang, Jun
Cc: Thomas Gleixner; Ingo Molnar; x86@...nel.org; Andrew Morton; Fleming, Matt; Paul Gortmaker; linux-kernel@...r.kernel.org
Subject: RE: [PATCH] To crash dump, we need keep other memory type except E820_RAM, because other type come from BIOS or firmware is used by other code(for example: PCI_MMCONFIG).
2) would make most sense to me, but I'd be okay with 3) as well.
"Zhang, Jun" <jun.zhang@...el.com> wrote:
>Hello, Anvin
>
>I want to explain why I modify in this place. In kexec, it pass three
>parameters, memmap=exactmap memmap=544K@64K memmap=64964K@...68K I
>think my patch modify the least code.
>Actually, there are some choise to fix it.
>1) my patch.
>2) modify kexec, only pass two parameters -- memmap=544K@64K
>memmap=64964K@...68K, in kernel setup_memory_map, we can remove RAM
>range.
>3) add extra optional, like memmap=REMOVERAM
>
>Which one do you like? Maybe you have better solution, please share it.
>Thanks!
>
>Best Regards!
>
>Jun Zhang
>Inet: 8821-4273
>Dir.Tel: 86-21-6116-4273
>Email: jun.zhang@...el.com
>
>-----Original Message-----
>From: H. Peter Anvin [mailto:hpa@...or.com]
>Sent: Wednesday, October 31, 2012 1:39 PM
>To: Zhang, Jun
>Cc: Thomas Gleixner; Ingo Molnar; x86@...nel.org; Andrew Morton;
>Fleming, Matt; Paul Gortmaker; linux-kernel@...r.kernel.org
>Subject: Re: [PATCH] To crash dump, we need keep other memory type
>except E820_RAM, because other type come from BIOS or firmware is used
>by other code(for example: PCI_MMCONFIG).
>
>On 10/30/2012 10:22 PM, Zhang, Jun wrote:
>> Hello, Anvin
>> You are right. Thanks!
>>
>> Hello, All
>> Please review it again. Thanks!
>>
>> From bf7506ac7e9ce0df0b915164dbb7a6d858ef2e40 Mon Sep 17 00:00:00
>> 2001
>> From: jzha144 <jun.zhang@...el.com>
>> Date: Wed, 31 Oct 2012 08:51:18 +0800
>> Subject: [PATCH] When we are doing a crash dump, we still need
>non-E820_RAM
>> memory type address information in order to do I/O. so only
>> remove all RAM ranges which need to be dumped.
>>
>> Signed-off-by: jzha144 <jun.zhang@...el.com>
>> ---
>> arch/x86/kernel/e820.c | 9 +++++++++
>> 1 files changed, 9 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index
>> df06ade..77be839 100644
>> --- a/arch/x86/kernel/e820.c
>> +++ b/arch/x86/kernel/e820.c
>> @@ -851,6 +851,15 @@ static int __init parse_memmap_opt(char *p)
>> * reset.
>> */
>> saved_max_pfn = e820_end_of_ram_pfn();
>> +
>> + /*
>> + * We are doing a crash dump, so remove all RAM ranges
>> + * as they are the ones that need to be dumped.
>> + * We still need all non-RAM information in order to do I/O.
>> + */
>> + e820_remove_range(0, ULLONG_MAX, E820_RAM, 1);
>> + userdef = 1;
>> + return 0;
>> #endif
>> e820.nr_map = 0;
>> userdef = 1;
>>
>
>The code is still wrong...
>
> -hpa
>
>
>--
>H. Peter Anvin, Intel Open Source Technology Center I work for Intel.
>I don't speak on their behalf.
--
Sent from my mobile phone. Please excuse brevity and lack of formatting.
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