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From: "Rich Caloggero" <rjc@MIT.EDU>
To: <speakup@braille.uwo.ca>
Subject: Multi-tasking
Date: Mon, 2 Jul 2001 13:55:09 -0400	[thread overview]
Message-ID: <002001c10320$22d0ca70$4c015112@vantaa> (raw)
In-Reply-To: <15164.26693.159819.537401@akp.selfhost.com>

Well, as far as I know, both windows and linux multi-task; linux has the
added advantage of being fully memory managed. Note, windows refers to the
consumer versions of windows (win95, 98, and milinium); NT and 2k are memory
managed, preemptive scheduling operating systems. The lack of memory
management is why, in most cases, windows becomes so unstable after being
"up" for a while.
In a memory managed environment, the hardware actually checks each memory
reference to make sure that the correct virtual address (the one supplied
with the referencing instruction) is mapped to a physical address. If no
physical address is mapped to that virtual address, it figures out whether a
mapping is possible by checking to see if the virtual address given is in
the correct range for the currently executing process.  If yes then it loads
the appropriate page from disk and continues; if not, it generates a page
fault and terminates the process. Note: this process is far more complex
than this; I'm sure I'm over simplifying and leaving a lot of stuff out.
Windows probably does some bound checking and it can swap, however it does
not make use of the memory management hardware on the processor; it does not
check every memory reference.
As far as scheduling goes, I believe they both do some sort of round robbin
preemptive scheduling, but linux probably has a better algorithm.


----- Original Message -----
From: "Ann Parsons" <akp@eznet.net>
To: <speakup@braille.uwo.ca>
Sent: Friday, June 29, 2001 7:36 AM
Subject: Re: New Braille Notetaker From Papenmeier


> Hi all,
>
> Well, Vic, you know that Windows is not a true multitasking
> invironment.  the processor pauses between tasks in order to allocate
> resources and memory while Linux and Unix really *are* multitasking
> environments.  they actually do run processes simultaneously and there
> is no pausing or checking of resources.
>
> Ann P.
>
> --
> Ann K. Parsons
> email:  akp@eznet.net ICQ Number:  33006854
> WEB SITE:  http://home.eznet.net/~akp
> "All that is gold does not glitter.  Not all those who wander are lost."
JRRT
>
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>



  reply	other threads:[~ UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
 New Braille Notetaker From Papenmeier Saqib Shaikh
 ` David Poehlman
   ` philwh
     ` Gregory Nowak
       ` Mike Calvo
       ` Ann Parsons
         ` Gregory Nowak
     ` Victor Tsaran
       ` Ann Parsons
         ` Rich Caloggero [this message]
           ` Multi-tasking Ann Parsons
           ` Multi-tasking Ann Parsons
             ` Multi-tasking David Poehlman
               ` Multi-tasking Ann Parsons
                 ` Multi-tasking David Poehlman
                   ` Multi-tasking Ann Parsons
                     ` Multi-tasking David Poehlman
                       ` Multi-tasking Ann Parsons
                         ` Multi-tasking David Poehlman
                         ` Multi-tasking Gregory Nowak
                           ` Multi-tasking David Poehlman
                           ` Multi-tasking Bruce Noblick
                           ` Multi-tasking Ann Parsons
                           ` Multi-tasking Scott Howell
                             ` Multi-tasking Bruce Noblick
                               ` Multi-tasking Gregory Nowak
                                 ` Multi-tasking Scott Howell
                     ` Multi-tasking Kirk Wood
                       ` Multi-tasking Ann Parsons
                         ` Multi-tasking Kirk Wood
                           ` Multi-tasking Ann Parsons
                 ` Multi-tasking Kirk Wood
                   ` Multi-tasking David Poehlman
           ` Multi-tasking Kirk Wood
 ` New Braille Notetaker From Papenmeier Gregory Nowak
   ` Janina Sajka
     ` Ann Parsons
       ` Janina Sajka
         ` Ann Parsons
       ` Ann Parsons
         ` Janina Sajka
           ` Stephen Dawes
   ` Mike Calvo
     ` David Poehlman
       ` Saqib Shaikh
     ` Janina Sajka
       ` Rich Caloggero
         ` Saqib Shaikh
           ` Janina Sajka
     ` Gregory Nowak
       ` Rich Caloggero
         ` Janina Sajka
           ` Saqib Shaikh
             ` Rich Caloggero
             ` Kirk Wood
             ` Janina Sajka
               ` David Poehlman
                 ` Stephen Dawes
                   ` Rich Caloggero
                     ` Geoff Shang
                   ` Janina Sajka
                     ` Geoff Shang
                     ` Angelo Sonnesso
                   ` Gregory Nowak
                   ` Victor Tsaran
                     ` Janina Sajka
                 ` Angelo Sonnesso
           ` David Poehlman
             ` Geoff Shang
         ` Jack
 ` Victor Tsaran
   ` philwh
     ` Victor Tsaran
       ` Gregory Nowak
       ` Kirk Wood
         ` David Poehlman
 Multi-tasking mo.valli
 ` Multi-tasking David Poehlman
 multi-tasking Bruce Noblick
 Multi-tasking Holmes, Steve
 ` Multi-tasking David Poehlman

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