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Davidlohr Bueso e4243b8062 ipc/sem: play nicer with large nsops allocations
Replacing semop()'s kmalloc for kvmalloc was originally proposed by
Manfred on the premise that it can be called for large (than order-1)
sizes.  For example, while Oracle recommends setting SEMOPM to a _minimum_
of 100, some distros[1] encourage the setting to be a factor of the amount
of db tasks (PROCESSES), which can get fishy for large systems (easily
going beyond 1000).

[1] An Example of Semaphore Settings
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Tuning_and_Optimizing_Red_Hat_Enterprise_Linux_for_Oracle_9i_and_10g_Databases/sect-Oracle_9i_and_10g_Tuning_Guide-Setting_Semaphores-An_Example_of_Semaphore_Settings.html

So let's just convert this to kvmalloc, just like the rest of the
allocations we do in ipc.  While the fallback vmalloc obviously involves
more overhead, this by far the uncommon path, and it's better for the user
than just erroring out with kmalloc.

Link: http://lkml.kernel.org/r/20170803184136.13855-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:51 -07:00
arch sh: defconfig: cleanup from old Kconfig options 2017-09-08 18:26:51 -07:00
block block/cfq: cache rightmost rb_node 2017-09-08 18:26:49 -07:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: af_alg - get_page upon reassignment to TX SGL 2017-08-22 15:03:27 +08:00
Documentation drivers/pps: aesthetic tweaks to PPS-related content 2017-09-08 18:26:51 -07:00
drivers drivers/pps: use surrounding "if PPS" to remove numerous dependency checks 2017-09-08 18:26:51 -07:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs vfat: deduplicate hex2bin() 2017-09-08 18:26:50 -07:00
include ipc: convert kern_ipc_perm.refcount from atomic_t to refcount_t 2017-09-08 18:26:51 -07:00
init init/main.c: extract early boot entropy from the passed cmdline 2017-09-08 18:26:50 -07:00
ipc ipc/sem: play nicer with large nsops allocations 2017-09-08 18:26:51 -07:00
kernel kcov: support compat processes 2017-09-08 18:26:51 -07:00
lib cpumask: make cpumask_next() out-of-line 2017-09-08 18:26:51 -07:00
mm mem/memcg: cache rightmost node 2017-09-08 18:26:49 -07:00
net Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2017-09-06 22:25:25 -07:00
samples media updates for v4.14-rc1 2017-09-07 12:53:14 -07:00
scripts checkpatch: add 6 missing types to --list-types 2017-09-08 18:26:50 -07:00
security audit/stable-4.14 PR 20170907 2017-09-07 20:48:25 -07:00
sound linux/kernel.h: move DIV_ROUND_DOWN_ULL() macro 2017-09-08 18:26:47 -07:00
tools tools/testing/selftests/kcmp/kcmp_test.c: add KCMP_EPOLL_TFD testing 2017-09-08 18:26:47 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM: update to new mmu_notifier semantic v2 2017-08-31 16:13:00 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS drivers/pps: aesthetic tweaks to PPS-related content 2017-09-08 18:26:51 -07:00
Makefile Merge branch 'docs-next' of git://git.lwn.net/linux 2017-09-03 21:07:29 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

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

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.