an existing object is re-referenced. LFUDA increments the cache ages when evicting blocks by setting it to the evicted object's key value. Thus, the cache age is always less than or equal to the minimum key value in the cache. Suppose when an object was frequently accessed in the past and now it becomes unpopular, it will remain in the cache for a long time thereby preventing the newly or less popular objects from replacing it. So this Dynamic aging is introduced to bring down the count of such objects thereby making them eligible for replacement. The advantage of LFUDA is it reduces the cache pollution caused by LFU when cache sizes are very small. When Cache sizes are large few replacement decisions are sufficient and cache pollution will not be a problem. RRIP-style policies RRIP-style policies form the basis for many other cache replacement policies including Hawkeye which won the CRC2 championship and was considered the most advanced cache replacement policy of its time. Re-Reference Interval Prediction (RRIP) RRIP is a very flexible policy proposed by Intel that attempts to provide good scan resistance while also allowing older cache lines that haven't been reused to be evicted. All cache lines have a prediction value called the RRPV (Re-Reference Prediction Value) that should correlate with when the line is expected to be reused. On insertion, this RRPV is usually high, so that if the line isn't reused soon, it will be evicted, this is done to prevent scans (large amounts of data that is used only once) from filling up the cache. When a cache line is reused, this RRPV is set to zero, indicating that this line has been reused once, and is likely to be reused again. On a cache miss, the line with the RRPV equal to the maximum possible RRPV is evicted (for example, with 3-bit values, the line with the RRPV of 23 = 7 is evicted), if no lines have this value, all RRPVs in the set are incremented by 1 until one reaches it. A tie breaker is needed, and usually it is the first line on the left. This increment is needed to make sure that older lines are aged properly and will be evicted if they aren't reused. Static RRIP (SRRIP) SRRIP inserts lines with an RRPV value of maxRRIP. This means that a line that has just been inserted will