更新时间:2021-09-13 22:18:43
尝试通过 CPU(即不通过 DMA)读取重复的大数据.喜欢:
Try to read repetitly large data via CPU (i.e. not by DMA). Like:
int main() {
const int size = 20*1024*1024; // Allocate 20M. Set much larger then L2
char *c = (char *)malloc(size);
for (int i = 0; i < 0xffff; i++)
for (int j = 0; j < size; j++)
c[j] = i*j;
}
但是取决于服务器,更大的问题可能是磁盘缓存(在内存中)然后是 L1/L2 缓存.在 Linux 上(例如)使用:
However depend on server a bigger problem may be a disk cache (in memory) then L1/L2 cache. On Linux (for example) drop using:
sync
echo 3 > /proc/sys/vm/drop_caches
生成什么都不做的大程序是微不足道的:
It is trivial to generate large program which do nothing:
#!/usr/bin/ruby
puts "main:"
200000.times { puts " nop" }
puts " xor rax, rax"
puts " ret"
以不同的名称运行几次(生成的代码不是脚本)应该可以完成工作
Running a few times under different names (code produced not the script) should do the work