WHAT HAPPENS IF THERE IS NO FREE FRAME? o Page replacement-find some page in memory,but not really in use,swap it out 。algorithm performance-want an algorithm which will result in minimum number of page faults o Same page may be brought into memory several timesWHAT HAPPENS IF THERE IS NO FREE FRAME?  Page replacement – find some page in memory, but not really in use, swap it out  algorithm  performance – want an algorithm which will result in minimum number of page faults  Same page may be brought into memory several times