Path: utzoo!attcan!utgpu!watmath!iuvax!mailrus!sharkey!atanasoff!hascall
From: hascall@atanasoff.cs.iastate.edu (John Hascall)
Newsgroups: comp.arch
Subject: Re: SCSI on steroids, mainframes move over
Message-ID: <1417@atanasoff.cs.iastate.edu>
Date: 30 Aug 89 15:45:15 GMT
References: <5932@pt.cs.cmu.edu> <3238@scolex.sco.COM> <26970@amdcad.AMD.COM> <1383@atanasoff.cs.iastate.edu> <452@ctycal.UUCP>
Reply-To: hascall@atanasoff.cs.iastate.edu.UUCP (John Hascall)
Followup-To: alt.dev.null
Organization: Iowa State Univ. Computation Center
Lines: 25

In article <452> ingoldsb@ctycal.COM (Terry Ingoldsby) writes:
}In article <1383>, hascall@atanasoff.cs.iastate.edu (John Hascall) writes:
}> In article <26970> davec@cayman.amd.com (Dave Christie) writes:
}> }In article <5932> butcher@g.gp.cs.cmu.edu (Lawrence Butcher) writes:
 
    [original thread on memory mapped I/O long since gone]
    [oops, that was the second thread, the first was SCSI]
 
...
} ....  I also note that most OSes seem preoccupied with managing
}memory and CPU load.  This was important in the days of expensive
}memory and slow CPUs.  What is often a bottleneck speed is I/O.
}For instance, if you want to take over a VMS machines it is quite
}easy.  Do a *whole* bunch of small QIOs (queue an I/O request to
}a disk drive), but don't wait for the result (eg. do a bunch of
}writes but don't block).


     That's what the quotas BIOLM and DIOLM are for, to limit the
     number of Buffered and Direct I/O's that a process can have
     active at any one time. 


John Hascall
ISU Comp Center