linux/Documentation
Michal Hocko 7635d9cbe8 mm, thp, proc: report THP eligibility for each vma
Userspace falls short when trying to find out whether a specific memory
range is eligible for THP.  There are usecases that would like to know
that
http://lkml.kernel.org/r/alpine.DEB.2.21.1809251248450.50347@chino.kir.corp.google.com
: This is used to identify heap mappings that should be able to fault thp
: but do not, and they normally point to a low-on-memory or fragmentation
: issue.

The only way to deduce this now is to query for hg resp.  nh flags and
confronting the state with the global setting.  Except that there is also
PR_SET_THP_DISABLE that might change the picture.  So the final logic is
not trivial.  Moreover the eligibility of the vma depends on the type of
VMA as well.  In the past we have supported only anononymous memory VMAs
but things have changed and shmem based vmas are supported as well these
days and the query logic gets even more complicated because the
eligibility depends on the mount option and another global configuration
knob.

Simplify the current state and report the THP eligibility in
/proc/<pid>/smaps for each existing vma.  Reuse
transparent_hugepage_enabled for this purpose.  The original
implementation of this function assumes that the caller knows that the vma
itself is supported for THP so make the core checks into
__transparent_hugepage_enabled and use it for existing callers.
__show_smap just use the new transparent_hugepage_enabled which also
checks the vma support status (please note that this one has to be out of
line due to include dependency issues).

[mhocko@kernel.org: fix oops with NULL ->f_mapping]
  Link: http://lkml.kernel.org/r/20181224185106.GC16738@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20181211143641.3503-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Oppenheimer <bepvte@gmail.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:50 -08:00
..
ABI zram: writeback throttle 2018-12-28 12:11:49 -08:00
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 selinux/stable-4.21 PR 20181224 2018-12-27 12:01:58 -08:00
aoe
arm ARM: SoC device tree updates for 4.20 2018-10-29 15:05:20 -07:00
arm64 arm64 festive updates for 4.21 2018-12-25 17:41:56 -08:00
auxdisplay
backlight
block Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
blockdev zram: writeback throttle 2018-12-28 12:11:49 -08:00
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 XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh 2018-12-06 08:26:17 -05:00
cpu-freq Documentation: cpu-freq: Frequencies aren't always sorted 2018-11-07 13:29:04 +01:00
cpuidle Documentation: admin-guide: PM: Add cpuidle document 2018-12-03 10:03:36 +01:00
crypto crypto: skcipher - remove remnants of internal IV generators 2018-12-23 11:52:45 +08:00
dev-tools kasan: update documentation 2018-12-28 12:11:44 -08:00
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 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-12-27 13:53:32 -08:00
doc-guide Documentation/sphinx: allow "functions" with no parameters 2018-06-30 07:52:42 -06:00
driver-api docs: driver-api: Add I3C documentation 2018-11-12 10:33:49 +01:00
driver-model gpio: Add devm_gpiod_unhinge() 2018-12-11 01:04:23 +00:00
early-userspace initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
EDID
extcon
fault-injection
fb This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
features MIPS: Enable IOREMAP_PROT config option for MIPS cpus 2018-11-05 10:15:28 -08:00
filesystems mm, thp, proc: report THP eligibility for each vma 2018-12-28 12:11:50 -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 Final changes to drm-misc-next for v4.21: 2018-12-07 11:23:05 +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
ide Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00
iio
infiniband
input Revert "Input: Add the REL_WHEEL_HI_RES event code" 2018-11-22 08:57:44 +01:00
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
media media fixes for v4.20-rc8 2018-12-25 13:11:30 -08:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2018-12-20 18:20:26 -08:00
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 Documentation: perf: Add documentation for ThunderX2 PMU uncore driver 2018-12-06 12:29:47 +00:00
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
rapidio
RCU doc: Fix "struction" typo in RCU memory-ordering documentation 2018-11-12 08:56:25 -08:00
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
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 mm: reclaim small amounts of memory when an external fragmentation event occurs 2018-12-28 12:11:48 -08:00
target
thermal
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 x86/speculation: Add prctl() control for indirect branch speculation 2018-11-28 11:57:13 +01:00
virtual x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID 2018-12-14 17:59:54 +01:00
vm Merge drm/drm-next into drm-intel-next-queued 2018-11-20 13:14:08 +02:00
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 Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 12:17:43 -08:00
xilinx Documentation: xilinx: Add documentation for eemi APIs 2018-10-09 13:26:05 +02:00
xtensa
.gitignore
atomic_bitops.txt
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
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
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
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt
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
video-output.txt
xillybus.txt
xz.txt
zorro.txt