Linux kernel stable tree
Go to file
NeilBrown de9e82c355 lib: add light-weight queuing mechanism.
lwq is a FIFO single-linked queue that only requires a spinlock
for dequeueing, which happens in process context.  Enqueueing is atomic
with no spinlock and can happen in any context.

This is particularly useful when work items are queued from BH or IRQ
context, and when they are handled one at a time by dedicated threads.

Avoiding any locking when enqueueing means there is no need to disable
BH or interrupts, which is generally best avoided (particularly when
there are any RT tasks on the machine).

This solution is superior to using "list_head" links because we need
half as many pointers in the data structures, and because list_head
lists would need locking to add items to the queue.

This solution is superior to a bespoke solution as all locking and
container_of casting is integrated, so the interface is simple.

Despite the similar name, this solution meets a distinctly different
need to kfifo.  kfifo provides a fixed sized circular buffer to which
data can be added at one end and removed at the other, and does not
provide any locking.  lwq does not have any size limit and works with
data structures (objects?) rather than data (bytes).

A unit test for basic functionality, which runs at boot time, is included.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: David Gow <davidgow@google.com>
Cc: linux-kernel@vger.kernel.org
Message-Id: <20230911111333.4d1a872330e924a00acb905b@linux-foundation.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:06 -04:00
arch Revert "x86/smp: Put CPUs into INIT on shutdown if possible" 2023-10-15 12:02:02 -07:00
block block: Don't invalidate pagecache for invalid falloc modes 2023-10-11 15:53:17 -06:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: sm2 - Fix crash caused by uninitialized context 2023-09-20 13:10:10 +08:00
Documentation lockd: introduce safe async lock op 2023-10-16 12:44:01 -04:00
drivers virtio_net: fix the missing of the dma cpu sync 2023-10-15 11:49:57 -07:00
fs SUNRPC: change how svc threads are asked to exit. 2023-10-16 12:44:04 -04:00
include lib: add light-weight queuing mechanism. 2023-10-16 12:44:06 -04:00
init workqueue: Changes for v6.6 2023-09-01 16:06:32 -07:00
io_uring io-wq: fully initialize wqe before calling cpuhp_state_add_instance_nocalls() 2023-10-05 14:11:18 -06:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel Two EEVDF fixes. 2023-10-14 15:21:34 -07:00
lib lib: add light-weight queuing mechanism. 2023-10-16 12:44:06 -04:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm Fourteen hotfixes, eleven of which are cc:stable. The remainder pertain 2023-10-01 13:33:25 -07:00
net SUNRPC: change service idle list to be an llist 2023-10-16 12:44:05 -04:00
rust Documentation work keeps chugging along; stuff for 6.6 includes: 2023-08-30 20:05:42 -07:00
samples VFIO updates for v6.6-rc1 2023-08-30 20:36:01 -07:00
scripts kbuild: remove stale code for 'source' symlink in packaging scripts 2023-10-01 23:06:06 +09:00
security KEYS: trusted: Remove redundant static calls usage 2023-10-10 11:19:43 -07:00
sound TTY/Serial driver fixes for 6.6-rc6 2023-10-15 09:11:39 -07:00
tools RISC-V Fixes for 6.6-rc6 2023-10-13 09:17:48 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap MAINTAINERS: update Matthieu's email address 2023-10-05 09:34:32 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Char/Misc driver fixes for 6.6-rc6 2023-10-15 09:07:27 -07:00
Makefile Linux 6.6-rc6 2023-10-15 13:34:39 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.