国产龙芯CPU的自研LoongArch架构对Linux 6.4的性能优化描述

#邮件原文部分如下所示
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LoongArch changes for v6.4

1, Better backtraces for humanization; 
2, Relay BCE exceptions to userland as SIGSEGV;
3, Provide kernel fpu functions;
4, Optimize memory ops (memset/memcpy/memmove);
5, Optimize checksum and crc32(c) calculation;
6, Add ARCH_HAS_FORTIFY_SOURCE selection;
7, Add function error injection support;
8, Add ftrace with direct call support;
9, Add basic perf tools support.

Note: There are merge conflicts in these files but can be simply fixed
by adjusting context around "static struct ftrace_ops direct":

  samples/ftrace/ftrace-direct-modify.c
  samples/ftrace/ftrace-direct-too.c
  samples/ftrace/ftrace-direct.c

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2, Relay BCE exceptions to userland as SIGSEGV; 将 BCE 异常作为 SIGSEGV 传递给 userland；

3, Provide kernel fpu functions; 提供内核 fpu 函数