linux-bl808/Documentation
Mike Kravetz 282f421438 hugetlbfs: clean up command line processing
With all hugetlb page processing done in a single file clean up code.

- Make code match desired semantics
  - Update documentation with semantics
- Make all warnings and errors messages start with 'HugeTLB:'.
- Consistently name command line parsing routines.
- Warn if !hugepages_supported() and command line parameters have
  been specified.
- Add comments to code
  - Describe some of the subtle interactions
  - Describe semantics of command line arguments

This patch also fixes issues with implicitly setting the number of
gigantic huge pages to preallocate.  Previously on X86 command line,

        hugepages=2 default_hugepagesz=1G

would result in zero 1G pages being preallocated and,

        # grep HugePages_Total /proc/meminfo
        HugePages_Total:       0
        # sysctl -a | grep nr_hugepages
        vm.nr_hugepages = 2
        vm.nr_hugepages_mempolicy = 2
        # cat /proc/sys/vm/nr_hugepages
        2

After this patch 2 gigantic pages will be preallocated and all the proc,
sysfs, sysctl and meminfo files will accurately reflect this.

To address the issue with gigantic pages, a small change in behavior was
made to command line processing.  Previously the command line,

        hugepages=128 default_hugepagesz=2M hugepagesz=2M hugepages=256

would result in the allocation of 256 2M huge pages.  The value 128 would
be ignored without any warning.  After this patch, 128 2M pages will be
allocated and a warning message will be displayed indicating the value of
256 is ignored.  This change in behavior is required because allocation of
implicitly specified gigantic pages must be done when the
default_hugepagesz= is encountered for gigantic pages.  Previously the
code waited until later in the boot process (hugetlb_init), to allocate
pages of default size.  However the bootmem allocator required for
gigantic allocations is not available at this time.

Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Sandipan Das <sandipan@linux.ibm.com>
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>	[s390]
Acked-by: Will Deacon <will@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Longpeng <longpeng2@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: http://lkml.kernel.org/r/20200417185049.275845-5-mike.kravetz@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03 20:09:46 -07:00
..
ABI ACPI updates for 5.8-rc1 2020-06-02 13:25:52 -07:00
accounting
admin-guide hugetlbfs: clean up command line processing 2020-06-03 20:09:46 -07:00
arm
arm64
block for-5.8-tag 2020-06-02 19:59:25 -07:00
bpf
cdrom
core-api padata: document multithreaded jobs 2020-06-03 20:09:45 -07:00
cpu-freq
crypto
dev-tools
devicetree drm pull for 5.8-rc1 2020-06-02 15:04:15 -07:00
doc-guide
driver-api Power management updates for 5.8-rc1 2020-06-02 13:17:23 -07:00
fault-injection
fb
features mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option 2020-06-03 20:09:43 -07:00
filesystems New code for 5.8: 2020-06-02 19:45:12 -07:00
firmware-guide
firmware_class
fpga
gpu
hid
hwmon
i2c
ia64
ide
iio
infiniband
input
isdn
kbuild
kernel-hacking
leds
livepatch
locking
m68k
maintainer
media
mhi
mips
misc-devices
netlabel
networking
nios2
nvdimm
openrisc
parisc
PCI
pcmcia
power Power management updates for 5.8-rc1 2020-06-02 13:17:23 -07:00
powerpc
process
RCU
riscv
s390
scheduler
scsi
security
sh
sound
sparc
sphinx
sphinx-static
spi
target
timers
trace
translations
usb
userspace-api
virt
vm docs/vm: update memory-models documentation 2020-06-03 20:09:44 -07:00
w1
watchdog
x86
xtensa
.gitignore
asm-annotations.rst
atomic_bitops.txt
atomic_t.txt
bus-virt-phys-mapping.txt
Changes
CodingStyle
conf.py
COPYING-logo
crc32.txt
docutils.conf
dontdiff
index.rst
Kconfig
kprobes.txt
logo.gif
lzo.txt
mailbox.txt
Makefile
memory-barriers.txt
nommu-mmap.txt
remoteproc.txt
rpmsg.txt
speculation.txt
static-keys.txt
SubmittingPatches
tee.txt
this_cpu_ops.txt
xz.txt