mmap of large file slows down system.

Rogier Wolff (R.E.Wolff@bitwizard.nl)
Sun, 22 Sep 1996 17:55:28 +0200 (MET DST)

I wrote a program that searches through a large file by first mmaping
the whole 256Mb file. It then steps sequentially through that file.

It seems that to the system this program is paging, and it bogs down
the whole system. When it would've been simply reading the file
sequentially, it wouldn't have caused the system to swap so much.

I'd submit a patch if it weren't that I have some work due real soon
now... :-)

Roger.