Re: how does mmap() work?

["Mark S. Waterbury" <mark_s_waterbury@xxxxxxxxx>]

Hi, Steve:

 

Perhaps you should read the excellent "White Papers" on the IBM AS/400

"Beyond Technology" web pages on IBM's iSeries web site, at:

http://www-1.ibm.com/servers/eserver/iseries/beyondtech/contents.htm 

(Table of Contents)

and especially the link:
http://www-1.ibm.com/servers/eserver/iseries/beyondtech/teraspace.htm
(titled:  Teraspace storage)

Here, I think you will find that teraspaces can in fact be "shared" between

processes, in some ways.  However, it appears that some of this functionality

may only be "visible" (made available) through the mmap() apis, etc.

This white paper hints that there is a new "address space" object at or below

the MI layer, that is used to implement teraspaces, etc. Very interesting!

 

Enjoy!

 

Mark

----- Original Message -----

From: Steve Richter

To: MI400@midrange.com

Sent: Tuesday, May 22, 2001 1:43 PM

Subject: Re: how does mmap() work?

Might I ask, why do you "care" how the mmap() API works?  Is it not enough

to know the purpose of the API, the parameters (the interface), and the results

that it provides, in order to make good use of this facility?

 

Hey Mark,

 

This api looks to be an advance for the iseries.  I would like to know how it was implemented in order to determine if it will perform well, to update my judgement of the quality of ibms technical mgmt. I also want to get a feel for how much of a say the ibm tech people have in deciding what is added to the os and how much time they were allowed to spend in implementing it.

 

I dont know much about teraspace and mmap() but I question why both?  Why is the teraspace limited to intraprocess while mmap() can work interprocess?

 

Is teraspace a stopgap that will now be replaced by the newer mmap( )?

 

Steve Richter