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makes MADV_SEQUENTIAL much more effective. I suggest that we start using MADV_SEQUENTIAL on system utilities that mmap their input files, and the I/O is predominantely sequential. Below is a test with 'cmp' on two relatively large binary files, where the files are so large that the caching is ineffective: + ls -l t1.xxx t2.xxx -rw-r--r-- 1 root wheel 65598384 Dec 10 12:13 t1.xxx -rw-r--r-- 1 root wheel 65598384 Dec 10 12:14 t2.xxx + time cmp t1.xxx t2.xxx 3.78user 0.70system 1:33.43elapsed 4%CPU + time cmpmadv t1.xxx t2.xxx 4.21user 1.05system 0:30.93elapsed 17%CPU This change is as a result of an observation made by BDE.