linux/Documentation
Michal Hocko 0158115f70 memcg, kmem: deprecate kmem.limit_in_bytes
Cgroup v1 memcg controller has exposed a dedicated kmem limit to users
which turned out to be really a bad idea because there are paths which
cannot shrink the kernel memory usage enough to get below the limit (e.g.
because the accounted memory is not reclaimable).  There are cases when
the failure is even not allowed (e.g.  __GFP_NOFAIL).  This means that the
kmem limit is in excess to the hard limit without any way to shrink and
thus completely useless.  OOM killer cannot be invoked to handle the
situation because that would lead to a premature oom killing.

As a result many places might see ENOMEM returning from kmalloc and result
in unexpected errors.  E.g.  a global OOM killer when there is a lot of
free memory because ENOMEM is translated into VM_FAULT_OOM in #PF path and
therefore pagefault_out_of_memory would result in OOM killer.

Please note that the kernel memory is still accounted to the overall limit
along with the user memory so removing the kmem specific limit should
still allow to contain kernel memory consumption.  Unlike the kmem one,
though, it invokes memory reclaim and targeted memcg oom killing if
necessary.

Start the deprecation process by crying to the kernel log.  Let's see
whether there are relevant usecases and simply return to EINVAL in the
second stage if nobody complains in few releases.

[akpm@linux-foundation.org: tweak documentation text]
Link: http://lkml.kernel.org/r/20190911151612.GI4023@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Lindroth <thomas.lindroth@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24 15:54:10 -07:00
..
ABI mm, slab: extend slab/shrink to shrink all memcg caches 2019-09-24 15:54:07 -07:00
accounting docs: add some documentation dirs to the driver-api book 2019-07-15 11:03:02 -03:00
admin-guide memcg, kmem: deprecate kmem.limit_in_bytes 2019-09-24 15:54:10 -07:00
arm Documentation/arm/samsung-s3c24xx: Remove stray U+FEFF character to fix title 2019-08-12 15:25:32 -06:00
arm64 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 11:42:15 -07:00
block docs: block: null_blk: enhance document style 2019-09-11 16:04:22 -06:00
bpf bpf/flow_dissector: document flags 2019-07-25 18:00:41 -07:00
cdrom docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
core-api docs: printk-formats: Stop encouraging use of unnecessary %h[xudi] and %hh[xudi] 2019-09-14 01:57:43 -06:00
cpu-freq Documentation: cpufreq: Update policy notifier documentation 2019-09-02 22:44:05 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-09-18 12:11:14 -07:00
dev-tools Merge branch 'pdf_fixes_v1' of https://git.linuxtv.org/mchehab/experimental into mauro 2019-07-22 13:51:20 -06:00
devicetree RTC for 5.4 2019-09-22 11:05:43 -07:00
doc-guide docs: remove extra conf.py files 2019-07-17 06:57:52 -03:00
driver-api This is the bulk of pin control changes for the v5.4 kernel 2019-09-19 14:19:33 -07:00
EDID docs: driver-api: add a series of orphaned documents 2019-07-15 11:03:02 -03:00
fault-injection docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
fb docs conversion for v5.3-rc1 2019-07-16 12:21:41 -07:00
features It's a somewhat calmer cycle for docs this time, as the churn of the mass 2019-09-17 16:22:26 -07:00
filesystems f2fs-for-5.4-rc1 2019-09-21 14:26:33 -07:00
firmware_class
firmware-guide Documentation: ACPI: DSD: Convert LED documentation to ReST 2019-08-20 23:53:46 +02:00
fpga Documentation: fpga: dfl: add descriptions for virtualization and new interfaces. 2019-09-03 19:35:42 -07:00
gpu Merge drm/drm-next into drm-intel-next-queued 2019-08-22 00:10:36 -07:00
hid docs: add some documentation dirs to the driver-api book 2019-07-15 11:03:02 -03:00
hwmon It's a somewhat calmer cycle for docs this time, as the churn of the mass 2019-09-17 16:22:26 -07:00
i2c docs: i2c: convert to ReST and add to driver-api bookset 2019-07-31 13:25:27 -06:00
ia64 docs: add SPDX tags to new index files 2019-07-15 11:03:03 -03:00
ide docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
iio docs: add some documentation dirs to the driver-api book 2019-07-15 11:03:02 -03:00
infiniband Documentation/infiniband: update name of some functions 2019-09-13 16:55:55 -03:00
input Input: docs: fix spelling mistake "potocol" -> "protocol" 2019-08-06 11:24:49 -06:00
ioctl fs-verity: add UAPI header 2019-07-28 16:59:16 -07:00
isdn docs: isdn: convert to ReST and add to kAPI bookset 2019-07-31 13:30:25 -06:00
kbuild Modules updates for v5.4 2019-09-22 10:34:46 -07:00
kernel-hacking docs: Add documentation for Symbol Namespaces 2019-09-10 10:30:49 +02:00
leds leds: core: Add support for composing LED class device names 2019-07-25 20:07:52 +02:00
livepatch docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
locking doc🔒 remove reference to clever use of read-write lock 2019-09-14 01:53:27 -06:00
m68k docs: README.buddha: convert to ReST and add to m68k book 2019-07-31 13:30:10 -06:00
maintainer docs: Fix typo on pull requests guide 2019-08-12 15:14:14 -06:00
media drm main pull for 5.4-rc1 2019-09-19 16:24:24 -07:00
mic docs: driver-api: add remaining converted dirs to it 2019-07-15 11:03:03 -03:00
mips Main MIPS changes for v5.4: 2019-09-22 09:30:30 -07:00
misc-devices Docs: misc: xilinx_sdfec: Add documentation 2019-08-15 17:54:38 +02:00
netlabel docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
networking Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
nios2 docs: nios2: add it to the main Documentation body 2019-07-31 13:31:51 -06:00
openrisc docs: openrisc: convert to ReST and add to documentation body 2019-07-31 13:30:20 -06:00
parisc docs: parisc: convert to ReST and add to documentation body 2019-07-31 13:30:15 -06:00
PCI Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-08-27 14:23:31 -07:00
pcmcia docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
power Merge branches 'pm-opp', 'pm-qos', 'acpi-pm', 'pm-domains' and 'pm-tools' 2019-09-17 09:49:19 +02:00
powerpc docs: powerpc: Add missing documentation reference 2019-09-17 23:59:34 +10:00
process It's a somewhat calmer cycle for docs this time, as the churn of the mass 2019-09-17 16:22:26 -07:00
RCU Merge branches 'consolidate.2019.08.01b', 'fixes.2019.08.12a', 'lists.2019.08.13a' and 'torture.2019.08.01b' into HEAD 2019-08-13 14:30:30 -07:00
riscv It's a somewhat calmer cycle for docs this time, as the churn of the mass 2019-09-17 16:22:26 -07:00
s390 Documentation/s390: remove outdated debugging390 documentation 2019-08-21 12:41:43 +02:00
scheduler sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices 2019-08-08 09:09:30 +02:00
scsi scsi: ufs: Documentation: Announce ufs-tool v1.0 2019-06-26 22:47:51 -04:00
security It's a somewhat calmer cycle for docs this time, as the churn of the mass 2019-09-17 16:22:26 -07:00
sh docs: remove extra conf.py files 2019-07-17 06:57:52 -03:00
sound sound updates for 5.4 2019-09-17 17:43:33 -07:00
sparc docs: add arch doc directories to the index 2019-07-15 11:03:01 -03:00
sphinx Documentation: sphinx: Don't parse socket() as identifier reference 2019-08-12 14:55:30 -06:00
sphinx-static
spi spi: docs: convert to ReST and add it to the kABI bookset 2019-07-31 14:13:13 -06:00
target docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
timers docs: add some directories to the main documentation index 2019-07-15 11:03:03 -03:00
trace Tracing updates: 2019-09-20 11:19:48 -07:00
translations doc: arm64: fix grammar dtb placed in no attributes region 2019-09-06 08:44:34 -06:00
usb USB: Move wusbcore and UWB to staging as it is obsolete 2019-08-08 07:52:01 +02:00
userspace-api docs: remove extra conf.py files 2019-07-17 06:57:52 -03:00
virt * More selftests 2019-09-11 18:06:15 +02:00
virtual cpuidle: add haltpoll governor 2019-07-30 17:27:37 +02:00
vm Merge branch 'odp_fixes' into hmm.git 2019-08-21 20:58:18 -03:00
w1 docs: w1: convert to ReST and add to the kAPI group of docs 2019-07-31 14:16:17 -06:00
watchdog Merge branch 'pdf_fixes_v1' of https://git.linuxtv.org/mchehab/experimental into mauro 2019-07-22 13:51:20 -06:00
x86 dma-mapping: fix filename references 2019-09-03 08:36:30 +02:00
xtensa docs: add arch doc directories to the index 2019-07-15 11:03:01 -03:00
.gitignore
atomic_bitops.txt
atomic_t.txt Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-08 16:12:03 -07:00
bus-virt-phys-mapping.txt
Changes
CodingStyle
conf.py docs: conf.py: only use CJK if the font is available 2019-07-17 06:57:51 -03:00
COPYING-logo docs: logo.txt: rename it to COPYING-logo 2019-07-15 09:20:27 -03:00
crc32.txt
debugging-modules.txt
debugging-via-ohci1394.txt
digsig.txt
DMA-API-HOWTO.txt docs: DMA-API-HOWTO.txt: fix an unmarked code block 2019-07-15 09:20:24 -03:00
DMA-API.txt dma-mapping: remove dma_release_declared_memory 2019-09-04 11:13:19 +02:00
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf doc-rst: Add missing newline at end of file 2019-06-20 14:16:56 -06:00
dontdiff kbuild: create *.mod with full directory path and remove MODVERDIR 2019-07-18 02:19:31 +09:00
futex-requeue-pi.txt
hwspinlock.txt hwspinlock: add the 'in_atomic' API 2019-06-29 21:08:14 -07:00
index.rst Main MIPS changes for v5.4: 2019-09-22 09:30:30 -07:00
io_ordering.txt
io-mapping.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
Kconfig docs: Kbuild/Makefile: allow check for missing docs at build time 2019-06-07 11:33:16 -06:00
kobject.txt
kprobes.txt Merge branch 'parisc-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2019-05-07 19:34:17 -07:00
kref.txt
logo.gif
lzo.txt
mailbox.txt
Makefile docs: Kbuild/Makefile: allow check for missing docs at build time 2019-06-07 11:33:16 -06:00
memory-barriers.txt docs: fix broken doc references due to renames 2019-07-17 06:57:51 -03:00
nommu-mmap.txt
padata.txt padata: allocate workqueue internally 2019-09-13 21:15:39 +10:00
percpu-rw-semaphore.txt
pi-futex.txt docs: locking: convert docs to ReST and rename to *.rst 2019-07-15 08:53:27 -03:00
preempt-locking.txt
rbtree.txt docs: rbtree.txt: fix Sphinx build warnings 2019-07-15 09:20:24 -03:00
remoteproc.txt remoteproc: add vendor resources handling 2019-06-29 12:02:17 -07:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
speculation.txt
static-keys.txt
SubmittingPatches
tee.txt Documentation: tee: Grammar s/the its/its/ 2019-06-07 11:23:38 -06:00
this_cpu_ops.txt
unaligned-memory-access.txt
xz.txt