In my work on improving performance of the Linux TCP stack (part of my involvement with HTCP) I never saw the congestion-control part in the performance monitor

In my work on improving performance of the Linux TCP stack (part of my involvement with HTCP) I never saw the congestion-control part in the performance monitoring. There are such long linked lists that one goes over that any small computation is lost in the noise, most of the time was spent reaching uncached memory lines.