Waterfall counters and an application to architectural vulnerability factor estimation
Described herein are waterfall counters and an application to architectural vulnerability factor (AVF) estimation. Waterfall counters count events that are generated at event generation logic. The waterfall counters are a combination of small, fast counters local to the event generation logic, and larger, global counters in fast memory. The local counters can be saturation or oscillation counters. When a local counter is saturated or evicted, the value from the local counter is added to the global counter. This addition can be done using logic local to the local or global counter. The waterfall counters provide a full-accuracy event count without the high bandwidth that is needed to maintain the global counters. An AVF estimation can be determined based on ratios from counts of read events, write events, and total events using the waterfall counters.