Re: teraspace, user spaces, etc.

["Steve Richter" <srichter@xxxxxxxxxxxxx>]

Thanks Paul, Alexie, Leif, Dr. Frank's book, et al.,

I understand the single lvl store concept, its advantages and disadvantages,
much better now.

I see that the 8 byte sls addr has a segment section ( 5 bytes ) and a
page/ofs section ( 3 bytes ).

A gigaspace would require a 4/4 split and a teraspace a 3/5 split of the 8
byte sls addr.

I am interested in knowing if the scheme of using the high order bits of the
8 byte addr as a way to determine where the split occurs was or was not
used.

The teraspace article in beyondtech says teraspaces are "allocated from a
reserved 1/16th portion of the systems 64 bit addr space".

Does that mean that the high order bits are used to locate the
segment/page-ofs split line in the 8 byte addr?

If so, why not or was the teraspace made a full mbr of the single level
store concept?

I admit that I could not make much headway into the teraspace article. It
appears that the teraspace has its own security system, what with policies,
super users, system users, common users.  It also seems to have its own
built in storage allocations schemes.

I am curious to know what were the requirements of the unix and nt
applications, other than the need for a large contiguous space, that the
single level store could not fulfill and that necessitated the teraspace
being more that just a big addr space.

thanks again,
Steve Richter


+---
| This is the MI Programmers Mailing List!
| To submit a new message, send your mail to MI400@midrange.com.
| To subscribe to this list send email to MI400-SUB@midrange.com.
| To unsubscribe from this list send email to MI400-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: dr2@cssas400.com
+---