linux+分配大页内存

cat /sys/kernel/mm/hugepages/

hugepages-2048kB/nr_overcommit_hugepages
hugepages-2048kB/nr_hugepages
hugepages-2048kB/memsize
hugepages-1048576kB/nr_overcommit_hugepages
hugepages-1048576kB/nr_hugepages
hugepages-1048576kB/memsize

cat /sys/kernel/mm/hugepages-<size>/nr_hugepages

cat /sys/kernel/mm/hugepages-2048kB/nr_hugepages

echo 1024 > /sys/kernel/mm/hugepages-2048kB/nr_hugepages

echo 1 > /sys/kernel/mm/hugepages-1048576kB/nr_hugepages

#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>

#define HUGETLB_FLAG_LARGE | MAP_HUGETLB
#define PAGE_SIZE 2147483648UL // 2GB

int main() {
    int fd = open("/dev/hugepages/my_hugepage_file", O_RDWR | O_CREAT, 0755);
    if (fd < 0) {
        perror("open");
        return 1;
    }

    // 预留 2GB 大页内存
    ftruncate(fd, PAGE_SIZE);

    void *addr = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE,
                      MAP_SHARED | MAP_HUGETLB, fd, 0);
    if (addr == MAP_FAILED) {
        perror("mmap");
        close(fd);
        return 1;
    }

    // 使用大页内存...

    munmap(addr, PAGE_SIZE);
    close(fd);
    return 0;
}

export HUGETLB_PATH=/mnt/hugepages

cat /proc/meminfo | grep Huge

cat /sys/kernel/mm/hugepages-<size>/nr_overcommit_hugepages

sudo mkdir -p /mnt/hugepages
sudo mount -t hugetlbfs nodev /mnt/hugepages
sudo chown root:root /mnt/hugepages