From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Feng Jiang <jiangfeng@kylinos.cn>
Cc: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu,
alex@ghiti.fr, kees@kernel.org, andy@kernel.org,
akpm@linux-foundation.org, ebiggers@kernel.org,
martin.petersen@oracle.com, ardb@kernel.org,
ajones@ventanamicro.com, conor.dooley@microchip.com,
samuel.holland@sifive.com, linus.walleij@linaro.org,
nathan@kernel.org, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH v2 00/14] riscv: optimize string functions and add kunit tests
Date: Tue, 13 Jan 2026 10:52:29 +0200 [thread overview]
Message-ID: <aWYHzYRdba03HSIH@smile.fi.intel.com> (raw)
In-Reply-To: <20260113082748.250916-1-jiangfeng@kylinos.cn>
On Tue, Jan 13, 2026 at 04:27:34PM +0800, Feng Jiang wrote:
> This series introduces optimized assembly implementations for strnlen,
> strchr, and strrchr on the RISC-V architecture. To support a rigorous
> verification process, the series also significantly expands the
> string_kunit test suite with both functional correctness tests and
> performance benchmarks.
>
> The patchset is organized as follows:
> - Refactoring (Patches 1-4): Extract generic C implementations for
> strlen, strnlen, strchr, and strrchr into exported __generic_* functions.
> - Correctness Testing (Patches 5-7): Extend string_kunit with detailed
> functional tests for the target functions.
> - Performance Benchmarking (Patches 8-11): Add a benchmarking framework
> to string_kunit to measure execution time across various string lengths.
> - RISC-V Optimizations (Patches 12-14): Provide the optimized assembly
> implementations for the RISC-V architecture.
...
> # string_test_strlen_bench: strlen performance (long, len: 2048, iters: 10000):
> # string_test_strlen_bench: arch-optimized: 14100 ns
> # string_test_strlen_bench: generic C: 35605600 ns
> # string_test_strlen_bench: speedup: 2525.21x
Doesn't sound right. I think you measured cache performance and not your algo.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-01-13 8:52 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-13 8:27 [PATCH v2 00/14] riscv: optimize string functions and add kunit tests Feng Jiang
2026-01-13 8:27 ` [PATCH v2 01/14] lib/string: extract generic strlen() into __generic_strlen() Feng Jiang
2026-01-13 8:33 ` Andy Shevchenko
2026-01-14 0:01 ` Eric Biggers
2026-01-14 1:41 ` Feng Jiang
2026-01-14 7:07 ` Andy Shevchenko
2026-01-14 10:10 ` David Laight
2026-01-15 6:50 ` Feng Jiang
2026-01-15 6:55 ` Andy Shevchenko
2026-01-13 8:27 ` [PATCH v2 02/14] lib/string: extract generic strnlen() into __generic_strnlen() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 03/14] lib/string: extract generic strchr() into __generic_strchr() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 04/14] lib/string: extract generic strrchr() into __generic_strrchr() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 05/14] lib/string_kunit: add correctness test for strlen Feng Jiang
2026-01-13 8:27 ` [PATCH v2 06/14] lib/string_kunit: add correctness test for strnlen Feng Jiang
2026-01-13 8:41 ` Andy Shevchenko
2026-01-13 8:27 ` [PATCH v2 07/14] lib/string_kunit: add correctness test for strrchr() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 08/14] lib/string_kunit: add performance benchmark for strlen() Feng Jiang
2026-01-13 8:46 ` Andy Shevchenko
2026-01-14 6:14 ` Feng Jiang
2026-01-14 7:04 ` Feng Jiang
2026-01-14 7:21 ` Andy Shevchenko
2026-01-14 8:05 ` Feng Jiang
2026-01-14 10:21 ` David Laight
2026-01-15 6:24 ` Feng Jiang
2026-01-15 10:40 ` David Laight
2026-01-18 11:11 ` kernel test robot
2026-01-13 8:27 ` [PATCH v2 09/14] lib/string_kunit: add performance benchmark for strnlen() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 10/14] lib/string_kunit: add performance benchmark for strchr() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 11/14] lib/string_kunit: add performance benchmark for strrchr() Feng Jiang
2026-01-13 8:27 ` [PATCH v2 12/14] riscv: lib: add strnlen implementation Feng Jiang
2026-01-13 8:48 ` Andy Shevchenko
2026-01-13 8:27 ` [PATCH v2 13/14] riscv: lib: add strchr implementation Feng Jiang
2026-01-13 8:27 ` [PATCH v2 14/14] riscv: lib: add strrchr implementation Feng Jiang
2026-01-13 8:52 ` Andy Shevchenko [this message]
2026-01-15 4:43 ` [PATCH v2 00/14] riscv: optimize string functions and add kunit tests Joel Stanley
2026-01-19 9:24 ` Feng Jiang
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