34 lines
2.0 KiB
HTML
34 lines
2.0 KiB
HTML
<HTML>
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<HEAD>
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
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<META NAME="Generator" CONTENT="Microsoft Word 97">
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<META NAME="Template" CONTENT="C:\PROGRAM FILES\MICROSOFT OFFICE\OFFICE\html.dot">
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<META NAME="GENERATOR" CONTENT="Mozilla/4.01b6C [en] (X11; I; Linux 2.1.47 i486) [Netscape]">
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<TITLE>Processes and Process Context</TITLE>
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</HEAD>
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<BODY BGCOLOR="#FFFFFF" LINK="#0000FF" VLINK="#800080">
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<FONT COLOR="#3366FF"><FONT SIZE=+3>Multiprocessing</FONT></FONT>
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<P><FONT SIZE=+1>So far we have considered machines which have only a single
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processor (known as the Central Processor Unit). Becoming more common these
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days are multi-processor machines which may have a number of processors
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(for example four or thirty two) which may provide true concurrency to
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multiple tasks running on the machine. On these machines the <A HREF="schedule.html">scheduler</A>
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will arrange for the execution of processes to occur in a manner selected
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to take maximum advantage of the available processing capacity. Asymmetric
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multiprocessing (ASMP) operating systems typically select one processor
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to run operating system code, with the other processors running user jobs.
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Problems with such systems include a lack of portability of the operating
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system to other platforms. Symmetric multiprocessing systems (SMPs), which
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include Linux, Sun's Solaris and Windows NT each allow the operating system
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to run on any or all of the available processors, sharing memory between
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them. The central unit for execution on such machines is the thread, with
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multiple threads of a single process having the possibility to be spread
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across multiple processors. The scheduling task on an SMP computer can
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become extremely complex.</FONT>
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<DIV ALIGN=right><A HREF="multitask.html"><IMG SRC="../gx/flower/cyan_lef.gif" BORDER=0 HEIGHT=31 WIDTH=31></A><A HREF="page1.html"><IMG SRC="../gx/flower/cyan_up.gif" BORDER=0 HEIGHT=31 WIDTH=31></A><A HREF="context.html"><IMG SRC="../gx/flower/cyan_rig.gif" BORDER=0 HEIGHT=31 WIDTH=31></A></DIV>
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<BR>
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</BODY>
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</HTML>
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