linux/lib/raid6/test, branch v6.18

raid6: skip avx512 checks

2025-04-30T19:53:48Z

It is no longer necessary to check for CONFIG_AS_AVX512, since the minimum assembler version is now from binutils-2.30 and this always supports it. Acked-by: Mark Rutland Signed-off-by: Arnd Bergmann

raid6: Add LoongArch SIMD recovery implementation

2023-09-06T14:53:55Z

Similar to the syndrome calculation, the recovery algorithms also work on 64 bytes at a time to align with the L1 cache line size of current and future LoongArch cores (that we care about). Which means unrolled-by-4 LSX and unrolled-by-2 LASX code. The assembly is originally based on the x86 SSSE3/AVX2 ports, but register allocation has been redone to take advantage of LSX/LASX's 32 vector registers, and instruction sequence has been optimized to suit (e.g. LoongArch can perform per-byte srl and andi on vectors, but x86 cannot). Performance numbers measured by instrumenting the raid6test code, on a 3A5000 system clocked at 2.5GHz: > lasx 2data: 354.987 MiB/s > lasx datap: 350.430 MiB/s > lsx 2data: 340.026 MiB/s > lsx datap: 337.318 MiB/s > intx1 2data: 164.280 MiB/s > intx1 datap: 187.966 MiB/s Because recovery algorithms are chosen solely based on priority and availability, lasx is marked as priority 2 and lsx priority 1. At least for the current generation of LoongArch micro-architectures, LASX should always be faster than LSX whenever supported, and have similar power consumption characteristics (because the only known LASX-capable uarch, the LA464, always compute the full 256-bit result for vector ops). Acked-by: Song Liu Signed-off-by: WANG Xuerui Signed-off-by: Huacai Chen

raid6: Add LoongArch SIMD syndrome calculation

2023-09-06T14:53:55Z

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 Signed-off-by: WANG Xuerui Signed-off-by: Huacai Chen

raid6: test: only check for Altivec if building on powerpc hosts

2023-08-15T16:40:27Z

Altivec is only available for powerpc hosts, so only check for its availability when the host is powerpc, to avoid error messages being shown on architectures other than x86, arm or powerpc. Signed-off-by: WANG Xuerui Link: https://lore.kernel.org/r/20230731104911.411964-6-kernel@xen0n.name Signed-off-by: Song Liu

raid6: test: make sure all intermediate and artifact files are .gitignored

2023-08-15T16:40:27Z

Currently when the raid6test utility is built, the resulting binary and an int.uc file are not being ignored, which can get inadvertently committed as a result when one works on the raid6 code. Ignore them to make `git status` clean at all times. Signed-off-by: WANG Xuerui Link: https://lore.kernel.org/r/20230731104911.411964-5-kernel@xen0n.name Signed-off-by: Song Liu

raid6: test: cosmetic cleanups for the test Makefile

2023-08-15T16:40:27Z

Use tabs/spaces consistently: hard tabs for marking recipe lines only, spaces for everything else. Also, the OPTFLAGS declaration actually included the tabs preceding the line comment, making compiler invocation lines unnecessarily long. As the entire block of declarations are meant for ad-hoc customization (otherwise they would probably make use of `?=` instead of `=`), move the "Adjust as desired" comment above the block too to fix the long invocation lines. Signed-off-by: WANG Xuerui Link: https://lore.kernel.org/r/20230731104911.411964-4-kernel@xen0n.name Signed-off-by: Song Liu

lib/raid6/test/Makefile: Use $(pound) instead of \# for Make 4.3

2022-03-08T23:20:21Z

Buidling raid6test on Ubuntu 21.10 (ppc64le) with GNU Make 4.3 shows the errors below: $ cd lib/raid6/test/ $ make :1:1: error: stray ‘\’ in program :1:2: error: stray ‘#’ in program :1:11: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ \ before ‘<’ token [...] The errors come from the HAS_ALTIVEC test, which fails, and the POWER optimized versions are not built. That’s also reason nobody noticed on the other architectures. GNU Make 4.3 does not remove the backslash anymore. From the 4.3 release announcment: > * WARNING: Backward-incompatibility! > Number signs (#) appearing inside a macro reference or function invocation > no longer introduce comments and should not be escaped with backslashes: > thus a call such as: > foo := $(shell echo '#') > is legal. Previously the number sign needed to be escaped, for example: > foo := $(shell echo '\#') > Now this latter will resolve to "\#". If you want to write makefiles > portable to both versions, assign the number sign to a variable: > H := \# > foo := $(shell echo '$H') > This was claimed to be fixed in 3.81, but wasn't, for some reason. > To detect this change search for 'nocomment' in the .FEATURES variable. So, do the same as commit 9564a8cf422d ("Kbuild: fix # escaping in .cmd files for future Make") and commit 929bef467771 ("bpf: Use $(pound) instead of \# in Makefiles") and define and use a $(pound) variable. Reference for the change in make: https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57 Cc: Matt Brown Signed-off-by: Paul Menzel Signed-off-by: Song Liu

lib/raid6/test: fix multiple definition linking error

2022-03-08T23:20:21Z

GCC 10+ defaults to -fno-common, which enforces proper declaration of external references using "extern". without this change a link would fail with: lib/raid6/test/algos.c:28: multiple definition of `raid6_call'; lib/raid6/test/test.c:22: first defined here the pq.h header that is included already includes an extern declaration so we can just remove the redundant one here. Cc: Signed-off-by: Dirk Müller Reviewed-by: Paul Menzel Signed-off-by: Song Liu

x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2

2020-04-08T15:12:48Z

Now that the kernel specifies binutils 2.23 as the minimum version, we can remove ifdefs for AVX2 and ADX throughout. Signed-off-by: Jason A. Donenfeld Acked-by: Ingo Molnar Reviewed-by: Nick Desaulniers Signed-off-by: Masahiro Yamada

x86: remove always-defined CONFIG_AS_SSSE3

2020-04-08T15:01:59Z

CONFIG_AS_SSSE3 was introduced by commit 75aaf4c3e6a4 ("x86/raid6: correctly check for assembler capabilities"). We raise the minimal supported binutils version from time to time. The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum required binutils version to 2.21"). I confirmed the code in $(call as-instr,...) can be assembled by the binutils 2.21 assembler and also by LLVM integrated assembler. Remove CONFIG_AS_SSSE3, which is always defined. I added ifdef CONFIG_X86 to lib/raid6/algos.c to avoid link errors on non-x86 architectures. lib/raid6/algos.c is built not only for the kernel but also for testing the library code from userspace. I added -DCONFIG_X86 to lib/raid6/test/Makefile to cator to this usecase. Signed-off-by: Masahiro Yamada Reviewed-by: Jason A. Donenfeld Reviewed-by: Nick Desaulniers Acked-by: Ingo Molnar