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bf506e366d
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Vasily Averin bf506e366d ipc: remove memcg accounting for sops objects in do_semtimedop() 
commit 6a4746ba06 upstream.

Linus proposes to revert an accounting for sops objects in
do_semtimedop() because it's really just a temporary buffer
for a single semtimedop() system call.

This object can consume up to 2 pages, syscall is sleeping
one, size and duration can be controlled by user, and this
allocation can be repeated by many thread at the same time.

However Shakeel Butt pointed that there are much more popular
objects with the same life time and similar memory
consumption, the accounting of which was decided to be
rejected for performance reasons.

Considering at least 2 pages for task_struct and 2 pages for
the kernel stack, a back of the envelope calculation gives a
footprint amplification of <1.5 so this temporal buffer can be
safely ignored.

The factor would IMO be interesting if it was >> 2 (from the
PoV of excessive (ab)use, fine-grained accounting seems to be
currently unfeasible due to performance impact).

Link: https://lore.kernel.org/lkml/90e254df-0dfe-f080-011e-b7c53ee7fd20@virtuozzo.com/
Fixes: 18319498fd ("memcg: enable accounting of ipc resources")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 18:14:29 +01:00
arch KVM: x86: emulator: update the emulation mode after CR0 write 2022-11-10 18:14:29 +01:00
block block, bfq: protect 'bfqd->queued' by 'bfqd->lock' 2022-11-10 18:14:24 +01:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:13:17 +02:00
crypto crypto: akcipher - default implementation for setting a private key 2022-10-26 13:25:42 +02:00
Documentation tracing/histogram: Update document for KEYS_MAX size 2022-11-10 18:14:26 +01:00
drivers wifi: brcmfmac: Fix potential buffer overflow in brcmf_fweh_event_worker() 2022-11-10 18:14:29 +01:00
fs ext4,f2fs: fix readahead of verity data 2022-11-10 18:14:29 +01:00
include efi: random: reduce seed size to 32 bytes 2022-11-10 18:14:27 +01:00
init Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug 2022-06-09 10:21:25 +02:00
ipc ipc: remove memcg accounting for sops objects in do_semtimedop() 2022-11-10 18:14:29 +01:00
kernel kprobe: reverse kp->flags when arm_kprobe failed 2022-11-10 18:14:26 +01:00
lib dyndbg: drop EXPORTed dynamic_debug_exec_queries 2022-10-26 13:25:34 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages 2022-11-03 23:57:50 +09:00
net tcp/udp: Make early_demux back namespacified. 2022-11-10 18:14:26 +01:00
samples x86: Prepare inline-asm for straight-line-speculation 2022-07-25 11:26:29 +02:00
scripts kbuild: Add skip_encoding_btf_enum64 option to pahole 2022-10-28 12:57:12 +02:00
security capabilities: fix potential memleak on error path from vfs_getxattr_alloc() 2022-11-10 18:14:26 +01:00
sound ALSA: usb-audio: Add quirks for MacroSilicon MS2100/MS2106 devices 2022-11-10 18:14:24 +01:00
tools tools/nolibc/string: Fix memcmp() implementation 2022-11-10 18:14:26 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt kvm: Add support for arch compat vm ioctls 2022-10-30 09:41:15 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add Amir as xfs maintainer for 5.10.y 2022-07-02 16:39:22 +02:00
Makefile Linux 5.10.153 2022-11-03 23:57:54 +09:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.