所以我有一个测试程序，它将大量数据读入缓冲区并 mallocs 相应地缓冲。然而，它 malloc 在大尺寸上失败。
有办法解决这个问题吗？
感谢任何回复
设备/dev/sdc 是一个 2TB 的磁盘。
这里准备了2个编译代码:
#define _FILE_OFFSET_BITS 64
#define BLKGETSIZE64 _IOR(0x12,114,size_t)
#define _POSIX_C_SOURCE 200809L
#include <stdio.h>
#include <inttypes.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
int readdata(int fp,uint64_t seekpoint, uint64_t seekwidth) {
int16_t *buf;
buf=(int16_t *)malloc(seekwidth*sizeof(int16_t)+1);
if (buf==0) {
printf("ERROR malloc(%"PRIu64")\n",seekwidth*(sizeof(int16_t)));
return 3;
}
if (pread(fp,buf,seekwidth,seekpoint)==seekwidth) {
printf("SUCCES READING AT: %"PRIu64"| WITH READ WIDTH: %"PRIu64"\n",seekpoint,seekwidth);
free(buf);
return 1;
} else {
printf("ERROR READING AT: %"PRIu64"| WITH READ WIDTH: %"PRIu64"\n",seekpoint,seekwidth);
free(buf);
return 2;
}
}
int main() {
uint64_t readwith,
offset;
int fp=open("/dev/sdc",O_RDWR);
readwith=10000; offset=0;
readdata(fp,offset,readwith);
readwith=100000; offset=0;
readdata(fp,offset,readwith);
readwith=1000000; offset=0;
readdata(fp,offset,readwith);
readwith=10000000; offset=0;
readdata(fp,offset,readwith);
readwith=100000000; offset=0;
readdata(fp,offset,readwith);
readwith=1000000000; offset=0;
readdata(fp,offset,readwith);
readwith=10000000000; offset=0;
readdata(fp,offset,readwith);
close(fp);
}
我系统的输出是:
SUCCES READING AT: 0| WITH READ WIDTH: 10000
SUCCES READING AT: 0| WITH READ WIDTH: 100000
SUCCES READING AT: 0| WITH READ WIDTH: 1000000
SUCCES READING AT: 0| WITH READ WIDTH: 10000000
SUCCES READING AT: 0| WITH READ WIDTH: 100000000
SUCCES READING AT: 0| WITH READ WIDTH: 1000000000
ERROR READING AT: 0| WITH READ WIDTH: 10000000000
ERROR READING AT: 0| WITH READ WIDTH: 100000000000
ERROR READING AT: 0| WITH READ WIDTH: 1000000000000
ERROR READING AT: 0| WITH READ WIDTH: 10000000000000
ERROR READING AT: 0| WITH READ WIDTH: 100000000000000
ERROR READING AT: 0| WITH READ WIDTH: 1000000000000000
有时
ERROR malloc(2000000000)
ERROR READING AT: 0| WITH READ WIDTH: 10000000000
最佳答案
好吧，我会说你不能分配大小为 10000000000 的内存，因为那是 9536 MiB，我猜你没有那么多 RAM。
您可以考虑使用 STXXL .
The core of STXXL is an implementation of the C++ standard template library STL for external memory (out-of-core) computations, i. e., STXXL implements containers and algorithms that can process huge volumes of data that only fit on disks.
关于c - malloc 有时会失败。或者 pread 有时会失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22599925/