Go to file
WANG Xuerui 8f3f06dfd6 raid6: Add LoongArch SIMD syndrome calculation
The algorithms work on 64 bytes at a time, which is the L1 cache line
size of all current and future LoongArch cores (that we care about), as
confirmed by Huacai. The code is based on the generic int.uc algorithm,
unrolled 4 times for LSX and 2 times for LASX. Further unrolling does
not meaningfully improve the performance according to experiments.

Performance numbers measured during system boot on a 3A5000 @ 2.5GHz:

> raid6: lasx     gen() 12726 MB/s
> raid6: lsx      gen() 10001 MB/s
> raid6: int64x8  gen()  2876 MB/s
> raid6: int64x4  gen()  3867 MB/s
> raid6: int64x2  gen()  2531 MB/s
> raid6: int64x1  gen()  1945 MB/s

Comparison of xor() speeds (from different boots but meaningful anyway):

> lasx:    11226 MB/s
> lsx:     6395 MB/s
> int64x4: 2147 MB/s

Performance as measured by raid6test:

> raid6: lasx     gen() 25109 MB/s
> raid6: lsx      gen() 13233 MB/s
> raid6: int64x8  gen()  4164 MB/s
> raid6: int64x4  gen()  6005 MB/s
> raid6: int64x2  gen()  5781 MB/s
> raid6: int64x1  gen()  4119 MB/s
> raid6: using algorithm lasx gen() 25109 MB/s
> raid6: .... xor() 14439 MB/s, rmw enabled

Acked-by: Song Liu <song@kernel.org>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06 22:53:55 +08:00
Documentation
LICENSES
arch LoongArch: Add SIMD-optimized XOR routines 2023-09-06 22:53:55 +08:00
block Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
certs
crypto
drivers Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
fs Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
include raid6: Add LoongArch SIMD syndrome calculation 2023-09-06 22:53:55 +08:00
init
io_uring
ipc
kernel
lib raid6: Add LoongArch SIMD syndrome calculation 2023-09-06 22:53:55 +08:00
mm Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
net
rust
samples
scripts
security
sound
tools Merge tag 'md-next-20230814-resend' into loongarch-next 2023-08-30 17:35:54 +08:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
.rustfmt.toml
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile
README

README

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.