I read paper "LIRS:An Efficient Low Inter-reference Recency SetReplacement Policy. by Song Jiang" and "Clock-Pro by Rik Van Riel"
And from their website, I know that Clock_pro(the approximate version of LIRS) has been supported in linux kernel 2.6.9. Now my question is how to enable the clock_pro option in linux. As a result, the page replacement algorithm is clock_pro but not LRU.