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Mahesh Salgaonkar a4e92ce8e4 powerpc/fadump: Reservationless firmware assisted dump 
One of the primary issues with Firmware Assisted Dump (fadump) on Power
is that it needs a large amount of memory to be reserved. On large
systems with TeraBytes of memory, this reservation can be quite
significant.

In some cases, fadump fails if the memory reserved is insufficient, or
if the reserved memory was DLPAR hot-removed.

In the normal case, post reboot, the preserved memory is filtered to
extract only relevant areas of interest using the makedumpfile tool.
While the tool provides flexibility to determine what needs to be part
of the dump and what memory to filter out, all supported distributions
default this to "Capture only kernel data and nothing else".

We take advantage of this default and the Linux kernel's Contiguous
Memory Allocator (CMA) to fundamentally change the memory reservation
model for fadump.

Instead of setting aside a significant chunk of memory nobody can use,
this patch uses CMA instead, to reserve a significant chunk of memory
that the kernel is prevented from using (due to MIGRATE_CMA), but
applications are free to use it. With this fadump will still be able
to capture all of the kernel memory and most of the user space memory
except the user pages that were present in CMA region.

Essentially, on a P9 LPAR with 2 cores, 8GB RAM and current upstream:
[root@zzxx-yy10 ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           7557         193        6822          12         541        6725
Swap:          4095           0        4095

With this patch:
[root@zzxx-yy10 ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           8133         194        7464          12         475        7338
Swap:          4095           0        4095

Changes made here are completely transparent to how fadump has
traditionally worked.

Thanks to Aneesh Kumar and Anshuman Khandual for helping us understand
CMA and its usage.

TODO:
- Handle case where CMA reservation spans nodes.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-21 11:32:49 +11:00
..
ABI LED fixes for 4.20-rc2 2018-11-08 17:49:04 -06:00
accelerators ocxl: Document new OCXL IOCTLs 2018-06-03 20:40:33 +10:00
accounting psi: cgroup support 2018-10-26 16:26:32 -07:00
acpi ACPI: property: graph: Update graph documentation to use generic references 2018-07-23 12:44:52 +02:00
admin-guide powerpc/fsl: Add FSL_PPC_BOOK3E as supported arch for nospectre_v2 boot arg 2018-12-20 22:59:03 +11:00
aoe
arm ARM: SoC device tree updates for 4.20 2018-10-29 15:05:20 -07:00
arm64 Documentation/arm64: HugeTLB page implementation 2018-10-10 18:08:36 +01:00
auxdisplay Doc: misc-devices: move lcd-panel-cgram.txt to auxdisplay/ 2018-04-12 16:08:02 +02:00
backlight
block Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
blockdev This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-08-07 11:02:05 -07:00
bus-devices
cdrom Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
cgroup-v1 Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2018-10-25 17:15:46 -07:00
cma
connector
console Documentation: corrections to console/console.txt 2018-08-10 16:09:40 -06:00
core-api docs/boot-time-mm: remove bootmem documentation 2018-10-31 08:54:16 -07:00
cpu-freq cpufreq: Drop cpufreq_table_validate_and_show() 2018-04-10 08:40:45 +02:00
cpuidle cpuidle: Add definition of residency to sysfs documentation 2018-04-09 13:44:37 +02:00
crypto KEYS: Implement PKCS#8 RSA Private Key parser [ver #2] 2018-10-26 09:30:46 +01:00
dev-tools docs: dev-tools: coccinelle: Update documentation 2018-08-31 16:51:59 -06:00
device-mapper This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
devicetree Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-11-10 06:57:34 -06:00
doc-guide Documentation/sphinx: allow "functions" with no parameters 2018-06-30 07:52:42 -06:00
driver-api Char/Misc driver patches for 4.20-rc1 2018-10-26 09:11:43 -07:00
driver-model dmaengine: add a new helper dmaenginem_async_device_register 2018-07-30 10:50:22 +05:30
early-userspace initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
EDID
extcon
fault-injection Documentation: nvme: Documentation for nvme fault injection 2018-03-26 08:53:43 -06:00
fb This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
features ARM: 8777/1: Hook up SYNC_CORE functionality for sys_membarrier() 2018-07-11 11:02:08 +01:00
filesystems This pull request contains updates for UBIFS: 2018-11-04 14:46:04 -08:00
firmware_class
fmc Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
fpga docs: fpga: add a document for FPGA Device Feature List (DFL) Framework Overview 2018-07-15 13:55:44 +02:00
gpio Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
gpu Merge branch 'drm-next-4.20' of git://people.freedesktop.org/~agd5f/linux into drm-next 2018-09-21 09:52:53 +10:00
hid
hwmon hwmon: (ina3221) Read channel input source info from DT 2018-10-10 20:37:13 -07:00
i2c i2c: add i2c bus driver for NVIDIA GPU 2018-11-09 17:46:43 +01:00
ia64 ia64: doc: tweak whitespace for 'console=' parameter 2018-03-05 14:41:38 -08:00
ide Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
iio
infiniband Documentation/ABI: update infiniband sysfs interfaces 2018-02-23 08:18:33 -07:00
input Input: Add the REL_WHEEL_HI_RES event code 2018-09-05 10:12:07 +02:00
ioctl drm pull for 4.20-rc1 2018-10-28 17:49:53 -07:00
isdn Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
kbuild kbuild: remove unused cc-fullversion variable 2018-11-02 00:15:26 +09:00
kdump
kernel-hacking doc:it_IT: translation for kernel-hacking 2018-07-26 16:21:09 -06:00
laptops platform-drivers-x86 for v4.20-1 2018-11-01 08:42:21 -07:00
leds Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
lightnvm
livepatch livepatch: Remove not longer valid limitations from the documentation 2018-05-24 15:37:57 +02:00
locking This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
m68k Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
maintainer docs: Fix more broken references 2018-06-15 18:11:26 -03:00
md raid5-ppl: PPL support for disks with write-back cache enabled 2018-01-15 14:29:42 -08:00
media media updates for v4.20-rc1 2018-10-31 10:53:29 -07:00
memory-devices
mic
mips Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
misc-devices pci_endpoint_test: Add 2 ioctl commands 2018-07-19 11:46:57 +01:00
mmc Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
mtd Documentation: mtd: remove stale pxa3xx NAND controller documentation 2018-09-04 23:37:38 +02:00
namespaces
netlabel Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
networking Kbuild updates for v4.20 (2nd) 2018-11-03 10:47:33 -07:00
nfc
nios2
nvdimm
nvmem Documentation: nvmem: document cell tables and lookup entries 2018-09-28 15:14:54 +02:00
openrisc
parisc Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
PCI pci-v4.20-changes 2018-10-25 06:50:48 -07:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
perf drivers/bus: Move Arm CCN PMU driver 2018-03-06 17:26:15 +01:00
phy
platform
power This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
powerpc powerpc/fadump: Reservationless firmware assisted dump 2018-12-21 11:32:49 +11:00
pps
process The Compiler Attributes series 2018-11-01 18:34:46 -07:00
pti
ptp ptp: Fix documentation to match code. 2018-03-26 12:13:21 -04:00
rapidio Documentation: rapidio: move sysfs interface to ABI 2018-02-23 08:25:45 -07:00
RCU This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
riscv perf: riscv: Add Document for Future Porting Guide 2018-06-04 14:02:11 -07:00
s390 KVM updates for v4.20 2018-10-25 17:57:35 -07:00
scheduler This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
scsi SCSI misc on 20181024 2018-10-25 07:40:30 -07:00
security Merge branch 'next-keys2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2018-11-01 15:23:59 -07:00
serial TTY/Serial patches for 4.20-rc1 2018-10-29 10:42:20 -07:00
sh
sound ALSA: doc: Brush up the old writing-an-alsa-driver 2018-10-18 10:30:01 +02:00
sparc sparc64: Add support for ADI (Application Data Integrity) 2018-03-18 07:38:48 -07:00
sphinx Documentation/sphinx: allow "functions" with no parameters 2018-06-30 07:52:42 -06:00
sphinx-static docs: improve readability for people with poorer eyesight 2018-10-07 09:16:50 -06:00
spi Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
sysctl New gcc plugin: stackleak 2018-11-01 11:46:27 -07:00
target
thermal thermal: Add cooling device's statistics in sysfs 2018-04-02 21:49:01 +08:00
timers Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
trace The biggest change here is the updates to kprobes 2018-10-30 09:49:56 -07:00
translations This was a moderately busy cycle for docs, with the usual collection of 2018-08-14 14:29:31 -07:00
usb USB-serial updates for v4.19-rc1 2018-07-20 21:47:15 +02:00
userspace-api audit/stable-4.18 PR 20180605 2018-06-06 16:34:00 -07:00
virtual KVM updates for v4.20 2018-10-25 17:57:35 -07:00
vm slub: extend slub debug to handle multiple slabs 2018-10-26 16:25:19 -07:00
w1 Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
watchdog documentation: watchdog: add documentation for armada-37xx-wdt 2018-10-13 15:19:40 +02:00
wimax
x86 x86/mm: Move LDT remap out of KASLR region on 5-level paging 2018-11-06 21:35:11 +01:00
xilinx Documentation: xilinx: Add documentation for eemi APIs 2018-10-09 13:26:05 +02:00
xtensa xtensa: add support for KASAN 2017-12-16 22:37:12 -08:00
.gitignore
atomic_bitops.txt locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit() 2018-02-13 14:55:53 +01:00
atomic_t.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
Changes
clearing-warn-once.txt
CodingStyle
conf.py This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt Documentation: remove stale firmware API reference 2018-05-14 16:44:41 +02:00
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff
efi-stub.txt efi_stub: update documentation on dtb= parameter 2018-09-09 14:46:44 -06:00
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst docs: tidy up TOCs and refs to license-rules.rst 2018-08-31 16:50:50 -06:00
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt block: Track DISCARD statistics and output them in stat and diskstat 2018-07-18 08:44:22 -06:00
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt irqdomain: Kill CONFIG_IRQ_DOMAIN_DEBUG 2018-01-24 12:32:58 +01:00
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-per-CPU-kthreads.txt doc: Update removal of RCU-bh/sched update machinery 2018-08-30 10:59:48 -07:00
kobject.txt
kprobes.txt kprobes/Documentation: Fix various typos 2018-06-22 11:10:55 +02:00
kref.txt
ldm.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lsm.txt
lzo.txt
mailbox.txt
Makefile
memory-barriers.txt locking/memory-barriers: Replace smp_cond_acquire() with smp_cond_load_acquire() 2018-10-02 10:28:05 +02:00
men-chameleon-bus.txt
nommu-mmap.txt Documentation: nommu-map: Fix duplicate word typo 2018-06-26 09:01:27 -06:00
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pnp.txt
preempt-locking.txt Documentation: preempt-locking: Use better example 2018-10-12 11:35:47 -06:00
pwm.txt
rbtree.txt
remoteproc.txt
rfkill.txt rfkill: Fix several typos in documentation 2018-06-15 13:36:08 +02:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt Documentation: rtc: move iotcl interface documentation to ABI 2018-01-12 00:20:41 +01:00
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt Documentation: Document array_index_nospec 2018-01-30 21:54:28 +01:00
static-keys.txt
SubmittingPatches
svga.txt
switchtec.txt NTB: switchtec_ntb: Update switchtec documentation with prerequisites for NTB 2018-10-11 11:28:53 -05:00
sync_file.txt
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
vfio-mediated-device.txt vfio/mdev: Check globally for duplicate devices 2018-06-08 10:24:27 -06:00
vfio.txt vfio: fix documentation 2018-05-08 09:16:41 -06:00
video-output.txt
xillybus.txt
xz.txt
zorro.txt