From: Yohanes Santoso <ruby-talk@...>
Date: 2002-06-20T19:33:44+09:00
Subject: Re: Why is I/O slow?

Yohanes Santoso <ruby-talk@jenny-gnome.dyndns.org> writes:

In my previous post, please ignore the paragraph that starts with:

> On another note, mmap cannot be used as a generic reading 
> mechanism.

Here is my correction: 

On another note, mmap cannot be used as a generic reading
mechanism. mmap requires something of fixed size. So, accesing $stdin,
network socket, etc. will have to be done differently than accessing
other file-based objects. In the case of cat-ing, there won't be any
improvement since the file access is linear, not random. In fact,
hunting down mmap() in filemap.c (which gave me a headache) from linux
2.4.18 code makes me think that for strictly linear access, mmap will
suffer because of the overhead.

YS.