using System.Reflection;
using System.Diagnostics;

for(;;)
{
    Stopwatch sw = new Stopwatch();
    sw.Start();
    for (int i = 0; i < 1000000; i++) MethodBase.GetCurrentMethod();
    Console.WriteLine(sw.ElapsedMilliseconds.ToString());
}

        public static MethodBase? GetCurrentMethod()
        {
            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller;
            RuntimeMethodHandleInternal methodHandle = InternalGetCurrentMethod(new StackCrawlMarkHandle(ref stackMark));
            return methodHandle.IsNullHandle() ? null : RuntimeType.GetMethodBase(null, methodHandle);
        }