Commit Graph

3 Commits

Author SHA1 Message Date
Jisheng Zhang d0fdc20b04
riscv: select DCACHE_WORD_ACCESS for efficient unaligned access HW
DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.

This patch implements support for load_unaligned_zeropad in much the
same way as has been done for arm64.

Here is the test program and step:

 $ cat tt.c
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #define ITERATIONS 1000000

 #define PATH "123456781234567812345678123456781"

 int main(void)
 {
         unsigned long i;
         struct stat buf;

         for (i = 0; i < ITERATIONS; i++)
                 stat(PATH, &buf);

         return 0;
 }

 $ gcc -O2 tt.c
 $ touch 123456781234567812345678123456781
 $ time ./a.out

Per my test on T-HEAD C910 platforms, the above test performance is
improved by about 7.5%.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20231225044207.3821-3-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09 20:18:20 -08:00
Thomas Gleixner 50acfb2b76 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation version 2 this program is distributed
  in the hope that it will be useful but without any warranty without
  even the implied warranty of merchantability or fitness for a
  particular purpose see the gnu general public license for more
  details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 97 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Palmer Dabbelt 5d8544e2d0 RISC-V: Generic library routines and assembly
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00