Linux kernel source tree
Find a file
David Laight f0bff2eb04 lib: test_mul_u64_u64_div_u64(): test both generic and arch versions
Change the #if in div64.c so that test_mul_u64_u64_div_u64.c can compile
and test the generic version (including the 'long multiply') on
architectures (eg amd64) that define their own copy.

Test the kernel version and the locally compiled version on all arch. 
Output the time taken (in ns) on the 'test completed' trace.

For reference, on my zen 5, the optimised version takes ~220ns and the
generic version ~3350ns.  Using the native multiply saves ~200ns and
adding back the ilog2() 'optimisation' test adds ~50ms.

Link: https://lkml.kernel.org/r/20251105201035.64043-7-david.laight.linux@gmail.com
Signed-off-by: David Laight <david.laight.linux@gmail.com>
Reviewed-by: Nicolas Pitre <npitre@baylibre.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Li RongQing <lirongqing@baidu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20 14:03:42 -08:00
arch lib: add mul_u64_add_u64_div_u64() and mul_u64_u64_div_u64_roundup() 2025-11-20 14:03:41 -08:00
block block-6.18-20251031 2025-10-31 12:57:19 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push contains the following changes: 2025-10-10 08:56:16 -07:00
Documentation dynamic_debug: add support for print stack 2025-11-12 10:00:16 -08:00
drivers i2c-for-6.18-rc5 2025-11-09 09:29:44 -08:00
fs ocfs2: validate cl_bpc in allocator inodes to prevent divide-by-zero 2025-11-20 14:03:41 -08:00
include lib: add mul_u64_add_u64_div_u64() and mul_u64_u64_div_u64_roundup() 2025-11-20 14:03:41 -08:00
init init/main.c: wrap long kernel cmdline when printing to logs 2025-11-12 10:00:16 -08:00
io_uring io_uring: fix regbuf vector size truncation 2025-11-07 17:17:13 -07:00
ipc ipc: create_ipc_ns: drop mqueue mount on sysctl setup failure 2025-11-12 10:00:15 -08:00
kernel kernel/hung_task: unexport sysctl_hung_task_timeout_secs 2025-11-20 14:03:41 -08:00
lib lib: test_mul_u64_u64_div_u64(): test both generic and arch versions 2025-11-20 14:03:42 -08:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm slab fix for 6.18-rc5 2025-11-07 08:01:58 -08:00
net Including fixes from bluetooth and wireless. 2025-11-06 08:52:30 -08:00
rust uaccess: decouple INLINE_COPY_FROM_USER and CONFIG_RUST 2025-11-12 10:00:16 -08:00
samples samples: fix coding style issues in Kconfig 2025-11-11 16:48:28 -08:00
scripts checkpatch: add IDR to the deprecated list 2025-11-20 14:03:41 -08:00
security integrity-v6.18 2025-10-05 10:48:33 -07:00
sound ASoC: Fixes for v6.18 2025-10-30 13:08:08 +01:00
tools hung_task: panic when there are more than N hung tasks at the same time 2025-11-12 10:00:14 -08:00
usr gen_init_cpio: Ignore fsync() returning EINVAL on pipes 2025-10-07 09:53:05 -07:00
virt KVM x86 fixes for 6.18: 2025-10-18 10:25:43 +02:00
.clang-format memblock: drop for_each_free_mem_pfn_range_in_zone_from() 2025-09-14 08:49:03 +03:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore compile_commands.json globally 2025-08-12 15:53:55 -07:00
.mailmap mailmap: add entry for Hao Ge 2025-11-12 10:00:17 -08:00
.pylintrc tools: docs: parse-headers.py: move it from sphinx dir 2025-08-29 15:54:42 -06:00
.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 CREDITS: update Martin's information 2025-11-12 10:00:14 -08:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: apply name and email address changes for Martin 2025-11-12 10:00:14 -08:00
Makefile Linux 6.18-rc5 2025-11-09 15:10:19 -08:00
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.