You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
231 lines
4.6 KiB
231 lines
4.6 KiB
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<HTML
|
|
><HEAD
|
|
><TITLE
|
|
>Simulating a Symmetric Multiprocessor (SMP) Machine</TITLE
|
|
><META
|
|
NAME="GENERATOR"
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
|
|
REL="HOME"
|
|
TITLE="Bochs User Manual"
|
|
HREF="index.html"><LINK
|
|
REL="UP"
|
|
TITLE="Tips and Techniques"
|
|
HREF="howto.html"><LINK
|
|
REL="PREVIOUS"
|
|
TITLE="Mounting a disk image using the loop device"
|
|
HREF="loop-device-usage.html"><LINK
|
|
REL="NEXT"
|
|
TITLE="Setting Up Networking in DLX Linux"
|
|
HREF="dlxlinux-networking.html"></HEAD
|
|
><BODY
|
|
CLASS="SECTION"
|
|
BGCOLOR="#FFFFFF"
|
|
TEXT="#000000"
|
|
LINK="#0000FF"
|
|
VLINK="#840084"
|
|
ALINK="#0000FF"
|
|
><DIV
|
|
CLASS="NAVHEADER"
|
|
><TABLE
|
|
SUMMARY="Header navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TH
|
|
COLSPAN="3"
|
|
ALIGN="center"
|
|
>Bochs User Manual</TH
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="left"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="loop-device-usage.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="80%"
|
|
ALIGN="center"
|
|
VALIGN="bottom"
|
|
>Chapter 8. Tips and Techniques</TD
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="right"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="dlxlinux-networking.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
></TABLE
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"></DIV
|
|
><DIV
|
|
CLASS="SECTION"
|
|
><H1
|
|
CLASS="SECTION"
|
|
><A
|
|
NAME="SMP"
|
|
>8.8. Simulating a Symmetric Multiprocessor (SMP) Machine</A
|
|
></H1
|
|
><P
|
|
>Bochs can now simulate an SMP machine when you use "--enable-smp" in the
|
|
configure command. SMP support was added by Bryce Denney, who
|
|
was very interested in watching a multiprocessor operating system work
|
|
at a low level. It should also be helpful to operating system developers
|
|
who are writing SMP drivers, or just for users who want to test drive
|
|
an SMP machine to see what it looks like.</P
|
|
><P
|
|
>Starting with Bochs 2.2.6 you can set up the number of processors in the
|
|
<TT
|
|
CLASS="FILENAME"
|
|
>bochsrc</TT
|
|
>. See <A
|
|
HREF="bochsrc.html#BOCHSOPT-CPU"
|
|
>Section 4.2.2</A
|
|
> how to
|
|
set up the number of processors.</P
|
|
><P
|
|
>It is important to understand that configuring bochs for 4 processors will NOT
|
|
make your single-threaded applications run faster in general! On the contrary,
|
|
it has to spend time simulating idle processors as well as the ones doing your
|
|
task. The point is to simulate an SMP system, not to speed up a uniprocessor
|
|
application.</P
|
|
><P
|
|
>What was required to make SMP work in Bochs?
|
|
|
|
<P
|
|
></P
|
|
><UL
|
|
><LI
|
|
><P
|
|
> local APIC on each processor with timer</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
> one I/O APIC model</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
> implement RDTSC (read time stamp counter)</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
> a data structure called the Intel Multiprocessor Configuration
|
|
must be present in BIOS memory space. An SMP-aware operating system probes BIOS
|
|
memory to find the structure, which contains information about how many
|
|
processors, their IDs, interrupt sources, etc. Starting with Bochs 2.2.5 these
|
|
structures are dynamicly created by Bochs.</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
> ACPI support is required to boot SMP system in most of modern
|
|
operating systems. For example WinXP 64 bit require ACPI support even for
|
|
single processor configuration. Still not supported by Bochs. (FIXME)</P
|
|
></LI
|
|
></UL
|
|
></P
|
|
><P
|
|
>What needs to be done to improve SMP support?
|
|
|
|
<P
|
|
></P
|
|
><UL
|
|
><LI
|
|
><P
|
|
>debugger support is still limited. For example, you can set breakpoints,
|
|
but you can't specify which processor you want to set the breakpoint for.</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>test on any possible SMP operating systems. Currently success reported for
|
|
Knoppix 4.0.2 and WinNT 4.0 SMP.</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>several parts of the APIC model which weren't needed before are not
|
|
implemented yet and cause a panic. If you boot linux 2.4.3 for
|
|
example, it says "panic: cluster model addressing not implemented".</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>A number of people have suggested using threads to simulate each CPU in
|
|
a different thread. Then on a real SMP machine, the threads can execute
|
|
in parallel. This is a great idea, but it's not done at present.</P
|
|
></LI
|
|
></UL
|
|
></P
|
|
></DIV
|
|
><DIV
|
|
CLASS="NAVFOOTER"
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"><TABLE
|
|
SUMMARY="Footer navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="loop-device-usage.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="index.html"
|
|
ACCESSKEY="H"
|
|
>Home</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="dlxlinux-networking.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
>Mounting a disk image using the loop device</TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="howto.html"
|
|
ACCESSKEY="U"
|
|
>Up</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
>Setting Up Networking in DLX Linux</TD
|
|
></TR
|
|
></TABLE
|
|
></DIV
|
|
></BODY
|
|
></HTML
|
|
>
|