use the binary from this C++ file produces:

```
// add.cpp
#include <cstdio>

char bulk[1 << 20];

int main()
{
	for (int i = 1; i < 1048576; i++) bulk[i] = bulk[i - 1] + 'a';
	printf("hello, world\n");
	return 0;
}
```

and compile it with

```
g++ add.cpp -o add -O2 -static
```

using GNU time 1.7 to monitor the usage

```
/usr/bin/time -v ./add
```

it reports that `add` uses ~1800 kbytes of maxrss, but uses busybox 1.34.1

```
time -v ./add
```

it reports that `add` uses ~7300 kbytes of maxrss. It's rather 4x more than the GNU time gives. I think there should not be too much gap between the two `time` functions.