目录

函数声明

函数原型与使用

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函数声明

void *malloc_huge_pages(size_t size);void free_huge_pages(void *ptr);
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函数原型与使用

#include <stdio.h>#include <assert.h> #include <stdlib.h> #include <string.h>#include <sys/mman.h>  #define HUGE_PAGE_SIZE (2 * 1024 * 1024)  #define ALIGN_TO_PAGE_SIZE(x) \    (((x) + HUGE_PAGE_SIZE - 1) / HUGE_PAGE_SIZE * HUGE_PAGE_SIZE)  void *malloc_huge_pages(size_t size) {     // Use 1 extra page to store allocation metadata     // (libhugetlbfs is more efficient in this regard)     size_t real_size = ALIGN_TO_PAGE_SIZE(size + HUGE_PAGE_SIZE);     char *ptr = (char *)mmap(NULL, real_size,                             PROT_READ | PROT_WRITE,                             MAP_PRIVATE | MAP_ANONYMOUS |                             MAP_POPULATE | MAP_HUGETLB, -1, 0);     if (ptr == MAP_FAILED) {         // The mmap() call failed. Try to malloc instead         ptr = (char *)malloc(real_size);         if (ptr == NULL)             return NULL;         real_size = 0;     } // Save real_size since mmunmap() requires a size parameter     *((size_t *)ptr) = real_size;      // Skip the page with metadata     return ptr + HUGE_PAGE_SIZE; } void free_huge_pages(void *ptr) {     if (ptr == NULL)         return;         // Jump back to the page with metadata     void *real_ptr = (char *)ptr - HUGE_PAGE_SIZE;      // Read the original allocation size     size_t real_size = *((size_t *)real_ptr);     assert(real_size % HUGE_PAGE_SIZE == 0);         if (real_size != 0)         // The memory was allocated via mmap()         // and must be deallocated via munmap()         munmap(real_ptr, real_size);     else         // The memory was allocated via malloc()         // and must be deallocated via free()         free(real_ptr); } int main(){	char *string = malloc_huge_pages(1024);		if(string == NULL) {		printf("error: malloc_huge_pages error.\n");	} 	strcpy(string, "Hello World!");	printf("string: %s\n", string); 	free_huge_pages(string); 	return 0;}
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