跨平台获取CPU cache line大小的方法

来源：互联网发布：百叶窗js 编辑：程序博客网时间：2024/05/27 20:42

Reprint：http://strupat.ca/2010/10/cross-platform-function-to-get-the-line-size-of-your-cache/

注意获得的cache line大小单位为字节。

#ifndef GET_CACHE_LINE_SIZE_H_INCLUDED#define GET_CACHE_LINE_SIZE_H_INCLUDED // Author: Nick Strupat// Date: October 29, 2010// Returns the cache line size (in bytes) of the processor, or 0 on failure #include <stddef.h>size_t cache_line_size(); #if defined(__APPLE__) #include <sys/sysctl.h>size_t cache_line_size() {size_t line_size = 0;size_t sizeof_line_size = sizeof(line_size);sysctlbyname("hw.cachelinesize", &line_size, &sizeof_line_size, 0, 0);return line_size;} #elif defined(_WIN32) #include <stdlib.h>#include <windows.h>size_t cache_line_size() {size_t line_size = 0;DWORD buffer_size = 0;DWORD i = 0;SYSTEM_LOGICAL_PROCESSOR_INFORMATION * buffer = 0; GetLogicalProcessorInformation(0, &buffer_size);buffer = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION *)malloc(buffer_size);GetLogicalProcessorInformation(&buffer[0], &buffer_size); for (i = 0; i != buffer_size / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION); ++i) {if (buffer[i].Relationship == RelationCache && buffer[i].Cache.Level == 1) {line_size = buffer[i].Cache.LineSize;break;}} free(buffer);return line_size;} #elif defined(linux) #include <stdio.h>size_t cache_line_size() {FILE * p = 0;p = fopen("/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size", "r");unsigned int i = 0;if (p) {fscanf(p, "%d", &i);fclose(p);}return i;} #else#error Unrecognized platform#endif #endif