• OpenCV => 3.3.0
• Operating System / Platform => Arch Linux (4.12.13-1-ARCH SMP PREEMPT x86_64 GNU/Linux)
• Compiler => gcc 7.2.0 and clang 5.0.0

Detailed description

It seems that a significant portion of memory is leaked in every thread.
The following code snippet consumes cca 100MB/s.

Steps to reproduce

#include <opencv2/opencv.hpp>
#include <future>
int main()
{
    while(true) {
        std::async(std::launch::async, []() { cv::Mat::zeros(1, 1, CV_32FC3); }).wait();
    }
}