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Davidlohr Bueso 60f3e00d25 sysv,ipc: cacheline align kern_ipc_perm 
Assign 'struct kern_ipc_perm' its own cacheline to avoid false sharing
with sysv ipc calls.

While the structure itself is rather read-mostly throughout the lifespan
of ipc, the spinlock causes most of the invalidations.  One example is
commit 31a7c4746e ("ipc/sem.c: cacheline align the ipc spinlock for
semaphores").  Therefore, extend this to all ipc.

The effect of cacheline alignment on sems can be seen in sembench, which
deals mostly with semtimedop wait/wakes is seen to improve raw
throughput (worker loops) between 8 to 12% on a 24-core x86 with over 4
threads.

Link: http://lkml.kernel.org/r/1486673582-6979-4-git-send-email-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>
2017-05-08 17:15:12 -07:00
arch powerpc/fadump: reuse crashkernel parameter for fadump memory reservation 2017-05-08 17:15:11 -07:00
block Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2017-05-06 11:25:08 -07:00
certs KEYS: Use structure to capture key restriction function and data 2017-04-04 14:10:10 -07:00
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
Documentation powerpc/fadump: update documentation about crashkernel parameter reuse 2017-05-08 17:15:11 -07:00
drivers drivers/misc/c2port/c2port-duramar2150.c: checking for NULL instead of IS_ERR() 2017-05-08 17:15:10 -07:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs pidns: expose task pid_ns_for_children to userspace 2017-05-08 17:15:12 -07:00
include sysv,ipc: cacheline align kern_ipc_perm 2017-05-08 17:15:12 -07:00
init initramfs: use vfs_stat/lstat directly 2017-05-08 17:15:12 -07:00
ipc ipc/shm: some shmat cleanups 2017-05-08 17:15:12 -07:00
kernel kcov: simplify interrupt check 2017-05-08 17:15:12 -07:00
lib lib/zlib_inflate/inftrees.c: fix potential buffer overflow 2017-05-08 17:15:12 -07:00
mm mm, compaction: finish whole pageblock to reduce fragmentation 2017-05-08 17:15:10 -07:00
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-05-05 11:08:43 -07:00
samples char/misc patches for 4.12-rc1 2017-05-04 19:15:35 -07:00
scripts checkpatch: improve the SUSPECT_CODE_INDENT test 2017-05-08 17:15:11 -07:00
security Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-05-03 08:50:52 -07:00
sound sound updates for 4.12-rc1 2017-05-03 11:58:59 -07:00
tools libnvdimm for 4.12 2017-05-05 18:49:20 -07:00
usr initramfs: provide a way to ignore image provided by bootloader 2017-05-08 17:15:12 -07:00
virt arm64 updates for 4.12: 2017-05-05 12:11:37 -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 Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap Staging/IIO patches for 4.12-rc1 2017-05-05 18:16:23 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS Staging/IIO patches for 4.12-rc1 2017-05-05 18:16:23 -07:00
Makefile make help: add tools help target 2017-05-08 17:15:10 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README 

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.