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Kuan-Wei Chiu 41ed780435 lib/sort: optimize heapsort for handling final 2 or 3 elements
After building the heap, the code continuously pops two elements from the
heap until only 2 or 3 elements remain, at which point it switches back to
a regular heapsort with one element popped at a time.  However, to handle
the final 2 or 3 elements, an additional else-if statement in the while
loop was introduced, potentially increasing branch misses.  Moreover, when
there are only 2 or 3 elements left, continuing with regular heapify
operations is unnecessary as these cases are simple enough to be handled
with a single comparison and 1 or 2 swaps outside the while loop.

Eliminating the additional else-if statement and directly managing cases
involving 2 or 3 elements outside the loop reduces unnecessary conditional
branches resulting from the numerous loops and conditionals in heapify.

This optimization maintains consistent numbers of comparisons and swaps
for arrays with even lengths while reducing swaps and comparisons for
arrays with odd lengths from 2.5 swaps and 1 comparison to 1.5 swaps and 1
comparison.

Link: https://lkml.kernel.org/r/20240527203011.1644280-4-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24 22:25:03 -07:00
arch - fix lseek in o32 compat mode 2024-06-23 07:20:02 -07:00
block block: unmap and free user mapped integrity via submitter 2024-06-12 11:00:50 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation The core gains placeholders for recently added functions when CONFIG_I2C 2024-06-23 11:06:01 -04:00
drivers bcache: remove heap-related macros and switch to generic min_heap 2024-06-24 22:25:00 -07:00
fs bcachefs: remove heap-related macros and switch to generic min_heap 2024-06-24 22:25:00 -07:00
include cpumask: make core headers including cpumask_types.h where possible 2024-06-24 22:25:02 -07:00
init gcc: disable '-Warray-bounds' for gcc-9 2024-06-15 10:43:04 -07:00
io_uring io_uring/rsrc: fix incorrect assignment of iter->nr_segs in io_import_fixed 2024-06-20 06:51:56 -06:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel lib min_heap: rename min_heapify() to min_heap_sift_down() 2024-06-24 22:24:59 -07:00
lib lib/sort: optimize heapsort for handling final 2 or 3 elements 2024-06-24 22:25:03 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memblock: fix fragility in checks for unset node ID 2024-06-23 10:32:24 -04:00
net nfsd-6.10 fixes: 2024-06-22 13:55:56 -07:00
rust rust: avoid unused import warning in rusttest 2024-06-11 23:33:28 +02:00
samples tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
scripts scripts/decode_stacktrace.sh: better support to ARM32 module stack trace 2024-06-24 22:25:00 -07:00
security lsm/stable-6.10 PR 20240617 2024-06-17 18:35:12 -07:00
sound ALSA: hda: Use imply for suggesting CONFIG_SERIAL_MULTI_INSTANTIATE 2024-06-21 12:04:19 +02:00
tools ARM: 2024-06-22 07:41:57 -07:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt KVM fixes for 6.10 2024-06-21 08:03:55 -04:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap bpf-for-netdev 2024-06-14 17:57:10 -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 MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
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 cpumask: split out include/linux/cpumask_types.h 2024-06-24 22:25:01 -07:00
Makefile Linux 6.10-rc5 2024-06-23 17:08:54 -04:00
README README: Fix spelling 2024-03-18 03:36:32 -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 reStructuredText 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.