[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference smurf::ase

Title:ase
Moderator:SMURF::GROSSO
Created:Thu Jul 29 1993
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2114
Total number of notes:7347

1943.0. "MAP 1GB of memory space via memchan?" by ROM01::OLD_CIPOLLA (Bruno Cipolla) Wed Mar 12 1997 10:35

    i would like to map 1GB (possibly more) of in-memory tables 
    to another node via
    the memory channel, so that when modifications are made to node A's
    memory they appear automagically on node B, where a simple read only
    portion of the application resides.
    if i remember well, currently memchan is restricted to 512Mbytes...	
    is it possible?
    
    Bruno
T.RTitleUserPersonal
Name
DateLines
1943.1Don't think so...NETRIX::"cherkus@buff.zk3.dec.com"Dave CherkusFri Mar 14 1997 17:0415
As I understand it, the 512 mb feature never got implemented -
the max is 128 mb.

The code that wrote the data structure would have to be very
carefully implemented, because MC only supports longword aligned
writes.  Also the MC error checking protocol would have to be
followed (writer will have to do synchs after the write completes
to insure there were no errors).

Finally, keep in mind that a handful of 8k pages are stolen by
the MC board for acces to internal registers, etc. and the MC
software primatives also steal pages for its internal use.

Dave
[Posted by WWW Notes gateway]