它是 一个采样测量时间段.在给定的时间段内，它报告一个或多个 GPU 内核处于活动状态(即运行)的时间百分比.

It is a sampled measurement over a time period. For a given time period, it reports what percentage of time one or more GPU kernel(s) was active (i.e. running).

它不会告诉您使用了多少 SM，或者忙"到什么程度.代码是，或者它正在做什么，或者它可能以什么方式使用了内存.

It doesn't tell you anything about how many SMs were used, or how "busy" the code was, or what it was doing exactly, or in what way it may have been using memory.

可以使用微基准测试类型的练习轻松验证上述声明(见下文).

The above claim(s) can be verified without too much difficulty using a microbenchmarking-type exercise (see below).

基于 Nvidia 文档，采样周期可能在 1 秒到 1/6 秒之间，具体取决于产品.但是，句点应该不会对您如何解释结果产生太大影响.

Based on the Nvidia docs, The sample period may be between 1 second and 1/6 second depending on the product. However, the period shouldn't make much difference on how you interpret the result.

此外，易挥发"一词与 nvidia-smi 中的此数据项无关.您误读了输出格式.

Also, the word "Volatile" does not pertain to this data item in nvidia-smi. You are misreading the output format.

这是支持我的主张的简单代码:

Here's a trivial code that supports my claim:

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

const long long tdelay=1000000LL;
const int loops = 10000;
const int hdelay = 1;

__global__ void dkern(){

  long long start = clock64();
  while(clock64() < start+tdelay);
}

int main(int argc, char *argv[]){

  int my_delay = hdelay;
  if (argc > 1) my_delay = atoi(argv[1]);
  for (int i = 0; i<loops; i++){
    dkern<<<1,1>>>();
    usleep(my_delay);}

  return 0;
}

在我的系统上，当我以 100 的命令行参数运行上述代码时，nvidia-smi 将报告 99% 的利用率.当我使用 1000 的命令行参数运行时，nvidia-smi 将报告 ~83% 的利用率.当我使用 10000 的命令行参数运行它时，nvidia-smi 将报告 ~9% 的利用率.

On my system, when I run the above code with a command line parameter of 100, nvidia-smi will report 99% utilization. When I run with a command line parameter of 1000, nvidia-smi will report ~83% utilization. When I run it with a command line parameter of 10000, nvidia-smi will report ~9% utilization.