If CPU usage 100% then close the all current running threads C#

Parallel.For(0, loopCount, parallelOptions, loopno =>
{
    for (int i = 0; i < tDSInput.Tables[0].Rows.Count; i++)
    {
     
        ////////Here i want to chk the CPU usage (if cpu usage is > 95%) then stop all running threads else normal execution.  
         
        
        var locker = new object();
        Monitor.Enter(locker);
        try
        {
            var tasks = Task.Factory.StartNew(() => ABC(),TaskCreationOptions.LongRunning)
            .ContinueWith(t => DEF(), TaskContinuationOptions.ExecuteSynchronously)
            .ContinueWith(t => GHI(), TaskContinuationOptions.ExecuteSynchronously)
            .ContinueWith(t => JKL(), TaskContinuationOptions.ExecuteSynchronously)
            ....
            ....
            ....
            ....
            ....
            ....
            .ContinueWith(t => XYZ(), TaskContinuationOptions.ExecuteSynchronously)
            Task.WaitAll(tasks);
        }
        finally
        {
            Monitor.Exit(locker);
        }
    } 
}