[PATCH 0/3] Make use of new memmap= kernel parameter syntax
H. Peter Anvin
hpa at zytor.com
Wed Jan 30 11:10:45 EST 2013
I don't see why this is "unnecessarily complex" compared to this stuff...
Thomas Renninger <trenn at suse.de> wrote:
>On Wednesday, January 30, 2013 06:40:46 AM H. Peter Anvin wrote:
>> The right thing to do as I have discussed with the people involved is
>to
>> modify the memory map data structure to have a new memory type ID for
>> memory which is to be dumped. That eliminates the need to put all
>this
>> info into the command line.
>As said before..., after looking closely into this I am convinced that
>passing a kexec-tools modified e820 table makes things unnecessary
>complex.
>
>So I suggest to still pass the original e820 table and kexec-tools
>only needs to pass the memory to use (usable) where the kdump kernel
>resides in via memmap=X at Y.
>This:
> - heavily cleans up the unnecesary reserved memory passing via memmap=
>- still provides a clean way of passing a valid e820 table through boot
> structures (no Linux kernel made up e820 type passing)
> - fixes mmconf and possible other bugs
>- provides the kdump kernel with all availabe info, it then knows
>about:
> original e820 map (all reserved, usable, etc. as specified by BIOS)
> kdump kernel memory area, former (crashed kernel) usable memory.
> - Keeps complexity as low as possible and at one place and does not
> involve kexec-tools as another error source (passing a badly
> mangled e820 table or not being able to consider stuff the kernel
> can when mangeling).
>
>Having that said I will reply to this mail with two kernel patches
>which implement this.
>The 3 kexec-tools patches would be more or less the same, only the
>string memmap=resetusable has to be exchanged to
>memmap=kdump_reserve_usable
>I wait until the kernel patches are in x86-tip and queued for
>3.9 and will resend them then.
>
>Please consider to apply the two kernel patches already.
>But I can also resend in a new thread.
>
> Thomas
>
>Ah yes, here the test results:
>Kdump specific boot parameter appends before:
>---------------------------------------------
>memmap=exactmap memmap=559K at 64K memmap=261560K at 638976K
>elfcorehdr=900536K memmap=488K#3034988K memmap=3076K#3067744K
>memmap=2048K#3106804K memmap=676K#3110812K
>memmap=4K#3111488K memmap=476K#3111492K memmap=4K#3111968K
>memmap=8K#3111972K memmap=4K#3111980K memmap=4K#3111984K
>memmap=92K#3111988K memmap=564K#3112080K
>
>Kdump specific boot parameter appends now:
>------------------------------------------
>memmap=kdump_reserve_usable,559K at 64K,261560K at 638976K elfcorehdr=900536K
>
>
>important parts of the serial console output of the
>---------------------------------------------------
>modified kdump kernel:
>----------------------
>[691036.954392] RIP [<ffffffff812f368d>] sysrq_handle_crash+0xd/0x20
>[691036.968140] RSP <ffff88042473de90>
>[691036.976113] CR2: 0000000000000000
>[ 0.000000] Initializing cgroup subsys cpuset
>[ 0.000000] Initializing cgroup subsys cpu
>[ 0.000000] Linux version 3.8.0-rc5-default+ (trenn at ett) (gcc
>version 4.5.1 20101208 [gcc-4_5-branch revision 167585] (SUSE Linux) )
>#4 SMP Wed Jan 30 15:45:36
>CET 2013
>[ 0.000000] Command line:
>root=/dev/disk/by-id/ata-Hitachi_HDS721016CLA382_JPAB40HM2KUK6B-part6
>console=tty0 console=ttyS0,57600 sysrq_always_enabled panic=100
>ignore_loglevel
>resume=/dev/disk/by-id/ata-Hitachi_HDS721016CLA382_JPAB40HM2KUK6B-part2
>apic=verbose debug vga=normal elevator=deadline sysrq=yes reset_devices
>
>irqpoll maxcpus=1
>memmap=kdump_reserve_usable,559K at 64K,261560K at 638976K elfcorehdr=900536K
>[ 0.000000] e820: BIOS-provided physical RAM map:
>[ 0.000000] BIOS-e820: [mem 0x0000000000000100-0x000000000009bbff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x000000000009bc00-0x000000000009ffff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000b93dafff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x00000000b93db000-0x00000000b9454fff]
>ACPI data
>[ 0.000000] BIOS-e820: [mem 0x00000000b9455000-0x00000000bb155fff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x00000000bb156000-0x00000000bb166fff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000bb167000-0x00000000bb3d7fff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x00000000bb3d8000-0x00000000bb6d8fff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bb6d9000-0x00000000bd9fcfff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x00000000bd9fd000-0x00000000bdbfcfff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bdbfd000-0x00000000bdcdcfff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x00000000bdcdd000-0x00000000bdde6fff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000bdde7000-0x00000000bde8ffff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bde90000-0x00000000bde90fff]
>ACPI data
>[ 0.000000] BIOS-e820: [mem 0x00000000bde91000-0x00000000bdf07fff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bdf08000-0x00000000bdf08fff]
>ACPI data
>[ 0.000000] BIOS-e820: [mem 0x00000000bdf09000-0x00000000bdf0afff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bdf0b000-0x00000000bdf0bfff]
>ACPI data
>[ 0.000000] BIOS-e820: [mem 0x00000000bdf0c000-0x00000000bdf0cfff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bdf0d000-0x00000000bdf23fff]
>ACPI data
>[ 0.000000] BIOS-e820: [mem 0x00000000bdf24000-0x00000000bdfb0fff]
>ACPI NVS
>[ 0.000000] BIOS-e820: [mem 0x00000000bdfb1000-0x00000000bdffffff]
>usable
>[ 0.000000] BIOS-e820: [mem 0x00000000be000000-0x00000000cfffffff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000fed19000-0x00000000fed19fff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x00000000ffa20000-0x00000000ffffffff]
>reserved
>[ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000083fffffff]
>usable
>[ 0.000000] debug: ignoring loglevel setting.
>[ 0.000000] e820: last_pfn = 0x840000 max_arch_pfn = 0x400000000
>[ 0.000000] e820: update [mem 0x00000000-0xfffffffffffffffe] usable
>==> kdump reserved
>[ 0.000000] e820: remove [mem 0x00010000-0x0009bbff]
>[ 0.000000] e820: remove [mem 0x27000000-0x36f6dfff]
>[ 0.000000] NX (Execute Disable) protection: active
>[ 0.000000] e820: user-defined physical RAM map:
>[ 0.000000] user: [mem 0x0000000000000100-0x000000000000ffff] kdump
>reserved
>[ 0.000000] user: [mem 0x0000000000010000-0x000000000009bbff] usable
>[ 0.000000] user: [mem 0x000000000009bc00-0x000000000009ffff]
>reserved
>[ 0.000000] user: [mem 0x00000000000e0000-0x00000000000fffff]
>reserved
>[ 0.000000] user: [mem 0x0000000000100000-0x0000000026ffffff] kdump
>reserved
>[ 0.000000] user: [mem 0x0000000027000000-0x0000000036f6dfff] usable
>[ 0.000000] user: [mem 0x0000000036f6e000-0x00000000b93dafff] kdump
>reserved
>[ 0.000000] user: [mem 0x00000000b93db000-0x00000000b9454fff] ACPI
>data
>[ 0.000000] user: [mem 0x00000000b9455000-0x00000000bb155fff] kdump
>reserved
>[ 0.000000] user: [mem 0x00000000bb156000-0x00000000bb166fff]
>reserved
>[ 0.000000] user: [mem 0x00000000bb167000-0x00000000bb3d7fff] kdump
>reserved
>[ 0.000000] user: [mem 0x00000000bb3d8000-0x00000000bb6d8fff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bb6d9000-0x00000000bd9fcfff] kdump
>reserved
>[ 0.000000] user: [mem 0x00000000bd9fd000-0x00000000bdbfcfff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bdbfd000-0x00000000bdcdcfff] kdump
>reserved
>[ 0.000000] user: [mem 0x00000000bdcdd000-0x00000000bdde6fff]
>reserved
>[ 0.000000] user: [mem 0x00000000bdde7000-0x00000000bde8ffff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bde90000-0x00000000bde90fff] ACPI
>data
>[ 0.000000] user: [mem 0x00000000bde91000-0x00000000bdf07fff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bdf08000-0x00000000bdf08fff] ACPI
>data
>[ 0.000000] user: [mem 0x00000000bdf09000-0x00000000bdf0afff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bdf0b000-0x00000000bdf0bfff] ACPI
>data
>[ 0.000000] user: [mem 0x00000000bdf0c000-0x00000000bdf0cfff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bdf0d000-0x00000000bdf23fff] ACPI
>data
>[ 0.000000] user: [mem 0x00000000bdf24000-0x00000000bdfb0fff] ACPI
>NVS
>[ 0.000000] user: [mem 0x00000000bdfb1000-0x00000000bdffffff] kdump
>reserved
>[ 0.000000] user: [mem 0x00000000be000000-0x00000000cfffffff]
>reserved
>[ 0.000000] user: [mem 0x00000000fec00000-0x00000000fec00fff]
>reserved
>[ 0.000000] user: [mem 0x00000000fed19000-0x00000000fed19fff]
>reserved
>[ 0.000000] user: [mem 0x00000000fed1c000-0x00000000fed1ffff]
>reserved
>[ 0.000000] user: [mem 0x00000000fee00000-0x00000000fee00fff]
>reserved
>[ 0.000000] user: [mem 0x00000000ffa20000-0x00000000ffffffff]
>reserved
>[ 0.000000] user: [mem 0x0000000100000000-0x000000083fffffff] kdump
>reserved
>[ 0.000000] SMBIOS 2.6 present.
>[ 0.000000] DMI: Intel Corporation S2600CP/S2600CP, BIOS
>SE5C600.86B.99.99.x040.111920110024 11/19/2011
>[ 0.000000] e820: update [mem 0x00000000-0x0000ffff] usable ==>
>reserved
>[ 0.000000] e820: remove [mem 0x000a0000-0x000fffff] usable
>[ 0.000000] No AGP bridge found
>...
>[ 2.220298] ACPI: bus type pci registered
>[ 2.229486] PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem
>0xc0000000-0xcfffffff] (base 0xc0000000)
>[ 2.250283] PCI: MMCONFIG at [mem 0xc0000000-0xcfffffff] reserved in
>E820
>[ 2.349583] PCI: Using configuration type 1 for base access
>...
>Copying data : [100 %]
>The dumpfile is saved to /root/abuild/dumps/2013-01-30-15:52/vmcore.
--
Sent from my mobile phone. Please excuse brevity and lack of formatting.
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