Differences between current version and predecessor to the previous major change of HowToSMPHOWTO.
Other diffs: Previous Revision, Previous Author, or view the Annotated Edit History
| Newer page: | version 3 | Last edited on Sunday, October 31, 2004 1:34:51 am | by AristotlePagaltzis | |
| Older page: | version 2 | Last edited on Friday, June 7, 2002 1:07:27 am | by perry | Revert |
@@ -1,3237 +1 @@
-
-
-
-Linux SMP HOWTO
-
-
-
-----
-
-!!!Linux SMP HOWTO
-
-!!David Mentreacute, David.Mentre@irisa.fr v1.12.1, 25 october 2000
-
-
-----
-''This HOWTO reviews main issues (and I hope solutions) related to SMP
-configuration under Linux.''
-----
-
-
-
-
-!!1. Licensing
-
-
-
-
-!!2. Introduction
-
-
-
-
-!!3. Questions related to any architectures
-
-
-*3.1 Kernel Side
-
-*3.2 User Side
-
-*3.3 SMP Programming
-
-
-
-
-
-!!4. x86 architecture specific questions
-
-
-*4.1 Why it doesn't work on my machine?
-
-*4.2 Possible causes of crash
-
-*4.3 Motherboard specific information
-
-*4.4 Low cost SMP Linux box (dual Celeron box)
-
-
-
-
-
-!!5. Sparc architecture specific questions
-
-
-*5.1 Which Sparc machines are supported ?
-
-*5.2 Specific problem related to Sparc SMP support
-
-*5.3 SMP specific limit with current kernel (2.2)
-
-
-
-
-
-!!6. PowerPC architecture specific questions
-
-
-*6.1 Which PPC machines are supported ?
-
-*6.2 Specific problem related to PPC SMP support
-
-
-
-
-
-!!7. Alpha architecture specific questions
-
-
-*7.1 Which Alpha machines are supported ?
-
-*7.2 Specific problem related to Alpha SMP support
-
-
-
-
-
-!!8. Useful pointers
-
-
-*8.1 Various
-
-*8.2 Multithreaded programs and library
-
-*8.3 SMP specific patches
-
-*8.4 Parallelizing/Optimizing Compilers for 586/686 machines
-
-
-
-
-
-!!9. Glossary
-
-
-*9.1 Definitions
-
-*9.2 Concepts
-
-
-
-
-
-!!10. What's new ?
-
-
-
-
-!!11. List of contributors
-----
-
-!!1. Licensing
-
-
-This document is made available under the terms of the GNU Free Documentation License.
-You should have received a copy with it. If not, it is available online at
-http://www.fsf.org/licenses/fdl.html.
-
-
-
-----
-
-!!2. Introduction
-
-
-Linux works on SMP (Symmetric Multi-Processors) machines. SMP support
-was introduced with kernel version 2., and has improved steadily ever
-since. The kernel locking granularity is much finer in 2.2.x than in
-2..x, which enables better performance when processes are accessing the
-kernel!
-
-
-
-
-
-HOWTO maintained by David Mentreacute (
-David.Mentre@irisa.fr). The latest
-edition of this HOWTO can be found at
-
-
-*
-http://www.irisa.fr/prive/mentre/smp-howto/ (France)
-*
-
-*
-http://www.phy.duke.edu/brahma/smp-faq/ (USA)
-*
-
-
-
-
-
-
-If you want to contribute to this HOWTO, I would prefer a diff against the
-SGML version of this
-document, but any remarks (in plain text) will be greatly
-appreciated. If you send me an email about this HOWTO, please include a
-tag like
[[Linux SMP HOWTO
] in the Subject: field of your
-e-mail. It helps me to automatically sort mails (and you will have a faster
-reply ;)).
-
-
-
-
-
-This HOWTO is an improvement of a
-first draft made by __Chris
-Pirih__.
-
-
-
-
-
-All information contained in this HOWTO is provided "as is." All
-warranties, expressed, implied or statutory, concerning the accuracy of
-the information of the suitability for any particular use are hereby
-specifically disclaimed. While every effort has been taken to ensure the
-accuracy of the information contained in this HOWTO, the authors assume
-no responsibility for errors or omissions, or for damages resulting from
-the use of the information contained herein.
-
-
-
-----
-
-!!3. Questions related to any architectures
-
-
-
-
-!!3.1 Kernel Side
-
-
-
-
-
-
-
-
-
-
-
-
-# __Does Linux support multi-threading? If I start two or more
-processes, will they be distributed among the available CPUs?__
-
-
-Yes. Processes and kernel-threads are distributed among processors.
-User-space threads are not.
-
-
-
-
-#
-
-# __What kind of architectures are supported in SMP?__
-
-
-
-
-; __From __Alan Cox__:__:
-
-SMP is supported in 2.0 on the hypersparc (SS20, etc.) systems and Intel
-486, Pentium or higher machines which are Intel MP1.1/1.4
-compliant. __Richard Jelinek__ adds: right now, systems have been
-tested up to 4 CPUs and the MP standard (and so Linux) theoretically
-allows up to 16 CPUs.
-
-
-SMP support for !UltraSparc, !SparcServer, Alpha and PowerPC machines is
-in available in 2.2.x.
-
-
-
-; __From __Ralf Baumlchle__:__:
-
-MIPS, m68k and ARM does not
-support SMP; the latter two probly won't ever.
-
-
-That is, I'm going to hack on MIPS-SMP as soon as I get a SMP box ...
-
-
-
-
-
-#
-
-# __How do I make a Linux SMP kernel?__
-
-
-Most Linux distributions don't provide a ready-made SMP-aware kernel,
-which means that you'll have to make one yourself. If you haven't made
-your own kernel yet, this is a great reason to learn how. Explaining
-how to make a new kernel is beyond the scope of this document; refer to
-the Linux Kernel Howto for more information. (__C. Polisher__)
-
-
-In kernel series 2.0 up to but not including 2.1.132, uncomment the
-SMP=1 line in the main Makefile (/usr/src/linux/Makefile).
-
-
-In the 2.2 version, configure the kernel and answer "yes" to the
-question "Symmetric multi-processing support" (__Michael Elizabeth
-Chastain__).
-
-
-AND
-
-
-enable real time clock support by configuring the "RTC support" item (in
-"Character Devices" menu) (from __Robert G. Brown__). Note that
-inserting RTC support actually doesn't afaik prevent the known problem
-with SMP clock drift, but enabling this feature prevents lockup when the
-clock is read at boot time. A note from __Richard Jelinek__ says
-also that activating the Enhanced RTC is necessary to get the second CPU
-working (identified) on some original Intel Mainboards.
-
-
-AND
-
-
-(x86 kernel) do NOT enable APM (advanced power management)! APM and SMP
-are not compatible, and your
-system will almost certainly (or at least probably ;)) crash
-while booting if APM is enabled (__Jakob Oestergaard__). __Alan
-Cox__ confirms this : 2.1.x turns APM off for SMP boxes. Basically
-APM is undefined in the presence of SMP systems, and anything could
-occur.
-
-
-AND
-
-
-(x86 kernel) enable "MTRR (Memory Type Range Register) support". Some
-BIOS are buggy as they do not activate cache memory for the second
-processor. The MTRR support contains code that solves such processor
-misconfiguration.
-
-
-
-
-
-
-
-
-You must rebuild all your kernel and kernel modules when changing to and
-from SMP mode. Remember to make modules and make
-modules_install (from __Alan Cox__).
-
-
-
-
-
-If you get module load errors, you probably did not rebuild and/or
-re-install your modules. Also with some 2.2.x kernels people have
-reported problems when changing the compile from SMP back to UP
-(uni-processor). To fix this, save your .config file, do ''make
-mrproper'', restore your ''.config'' file, then remake your
-kernel (''make dep'', etc.) (__Wade Hampton__). Do not forget
-to run lilo after copying your new kernel.
-
-
-Recap:
-----
-
-make config # or menuconfig or xconfig
-make dep
-make clean
-make bzImage # or whatever you want
-# copy the kernel image manually then RUN LILO
-# or make lilo
-make modules
-make modules_install
-
-----
-
-
-
-
-
-
-
-#
-
-# __How do I make a Linux __non__-SMP kernel?__
-
-
-In the 2.0 series, __comment__ the SMP=1 line in the main
-Makefile (/usr/src/linux/Makefile).
-
-
-In the 2.2 series, configure the kernel and answer "no" to the question
-"Symmetric multi-processing support" (__Michael Elizabeth
-Chastain__).
-
-
-
-
-
-
-
-
-
-
-
-You must rebuild all your kernel and kernel modules when changing to and
-from SMP mode. Remember to make modules and make
-modules_install and remember to run lilo. See notes above about
-possible configuration problems.
-
-
-
-
-
-
-
-#
-
-# __How can I tell if it worked?__
-
-
-
-
-cat /proc/cpuinfo
-
-
-
-
-
-
-Typical output (dual PentiumII):
-----
-
-processor :
-cpu : 686
-model : 3
-vendor_id : !GenuineIntel
-[[...]
-bogomips : 267.06
-processor : 1
-cpu : 686
-model : 3
-vendor_id : !GenuineIntel
-[[...]
-bogomips : 267.06
-
-----
-
-
-
-
-#
-
-# __What is the status of converting the kernel toward finer
-grained locking and multithreading?__
-
-
-Linux kernel version 2.2 has signal handling, interrupts and some I/O stuff fine grain
-locked. The rest is gradually migrating. All the scheduling is SMP
-safe.
-
-
-
-
-
-Kernel version 2.3 (next 2.4) has really fine grained locking. In the 2.3 kernels
-the usage of the big kernel lock has basically disappeared, all major
-Linux kernel subsystems are fully threaded: networking, VFS, VM, IO,
-block/page caches, scheduling, interrupts, signals, etc. (__Ingo
-Molnar__)
-
-
-
-
-#
-
-# __Does Linux SMP support processor affinity?__
-
-
-
-
-
-
-
-; __Standard kernel__:
-
-No and Yes. There is no way to force a process onto specific CPU's but
-the linux scheduler has a processor bias for each process, which tends
-to keep processes tied to a specific CPU.
-
-
-
-; __Patch__:
-
-Yes. Look at
-PSET - Processor Sets for the Linux kernel:
-
-The goal of this project is to make a source compatible and functionally
-equivalent version of pset (as defined by SGI - partially removed from
-their IRIX 6.4 kernel) for Linux. This enables users to determine which
-processor or set of processors a process may run on. Possible uses
-include forcing threads to separate processors, timings, security (a
-`root' only CPU?) and probably more.
-
-
-
-It is focused around the syscall sysmp(). This function takes a number of
-parameters that determine which function is requested. Functions
-include:
-
-
-#* binding a process/thread to a specific CPU
-#*
-
-#* restricting a CPU's ability to execute some processes
-#*
-
-#* restricting a CPU from running at all
-#*
-
-#* forcing a cpu to run _only_ one process (and its children)
-#*
-
-#* getting information about a CPU's state
-#*
-
-#* creating/destroying sets of processors, to which processes may be
-bound
-#*
-
-
-
-
-
-
-
-
-
-#
-
-# __Where should one report SMP bugs to?__
-
-
-Please report bugs to linux-smp@vger.kernel.org.
-
-
-
-
-#
-
-# __What about SMP performance?__
-
-
-If you want to gauge the performance of your SMP system, you can run some tests made by
-Cameron !MacKinnon and available at
-http://www.phy.duke.edu/brahma/benchmarks.smp.
-
-
-Also have a look at this article by Bryant, Hartner, Qi and
-Venkitachalam that compares 2.2 and 2.3/2.4 UP and SMP kernels :
-SMP Scalability Comparisons of Linux¨ Kernels 2.2.14 and 2.3.99
-(__Ray Bryant__) (You'll find also a copy
-)
-
-
-
-
-#
-
-
-
-
-
-
-
-
-!!3.2 User Side
-
-
-
-
-
-
-# __Do I really need SMP?__
-
-
-If you have to ask, you probably don't. :)
-Generally, multi-processor systems can provide better performance
-than uni-processor systems, but to realize any gains you need
-to consider many other factors besides the number of CPU's.
-For instance, on a given system, if the processor is generally
-idle much of the time due to a slow disk drive, then this system
-is "input/output bound", and probably won't benefit from additional
-processing power. If, on the other hand, a system has many
-simultaneously executing processes, and CPU utilization is very
-high, then you are likely to realize increased system performance.
-SCSI disk drives can be very effective when used with multiple
-processors, due to the way they can process multiple commands
-without tying up the CPU. (__C. Polisher__)
-
-
-
-
-#
-
-# __Do I get the same performance from 2-300 MHz processors
-as from one 600 MHz processor?__
-
-
-This depends on the application, but most likely not. SMP adds
-some overhead that a faster uniprocessor box would not incur
-(__Wade Hampton__).
-:)
-
-
-
-
-#
-
-# __How does one display mutiple cpu performance?__
-
-
-Thanks to __Samuel S. Chessman__, here are some useful utilities:
-
-; __Character based:__:
-
-
-http://www.cs.inf.ethz.ch/~rauch/procps.html
-
-Basically, it's procps v1.12.2 (top, ps, et. al.) and some patches to
-support SMP.
-
-
-For 2.2.x, __Gregory R. Warnes__ as made a patch available at
-http://queenbee.fhcrc.org/~warnes/procps
-
-
-
-; __Graphic:__:
-
-xosview-1.5.1 supports SMP. And kernels above 2.1.85 (included) the cpuX
-entry in /proc/stat file.
-
-
-The official homepage for xosview is:
-http://lore.ece.utexas.edu/~bgrayson/xosview.html
-
-
-You'll find a version patched for 2.2.x kernels by __Kumsup Lee__ :
-http://www.ima.umn.edu/~klee/linux/xosview-1.6.1-5a1.tgz
-
-
-By the way, you can't monitor processor scheduling precisely with xosview,
-as xosview itself causes a scheduling perturbation. (__H. Peter
-Anvin__)
-
-
-And __Rik van Riel__ tell us why:
-
-The answer is pretty simple. Basically there are 3
-processes involved:
-
-
-## the cpu hog (low scheduling priority because it eats CPU)
-##
-
-## xosview
-##
-
-## X
-##
-
-
-
-The CPU hog is running on one CPU. Then xosview wakes up
-(on the other CPU) and starts sending commands to X, which
-wakes up as well.
-
-
-Since both X and xosview have a much higher priority than
-the CPU hog, xosview will run on one CPU and X on the other.
-
-
-Then xosview stops running and we have an idle CPU --> Linux
-moves the CPU hog over to the newly idle CPU (X is still
-running on the CPU our hog was running on just before).
-
-
-
-
-
-
-
-
-#
-
-# __How can I enable more than 1 process for my kernel compile?__
-
-
-use:
-----
-
-# make [[modules|zImage|bzImages] MAKE="make -jX"
-where X=max number of processes.
-WARNING: This won't work for "make dep".
-
-----
-
-
-With a 2.2 like kernel, see also the file
-/usr/src/linux/Documentation/smp.txt for specific instruction.
-
-
-BTW, since running multiple compilers allows a machine with sufficient
-memory to use use the otherwise wasted CPU time during I/O caused delays,
-make MAKE="make -j 2" -j 2 actually helps even on uniprocessor
-boxes (from __Ralf Baumlchle__).
-
-
-
-
-#
-
-# __Why is the time given by the time command inaccurate?__
-(from __Joel Marchand__)
-
-
-In the 2.0 series, the result given by the time command is
-false. The sum user+system is right *but* the spreading between user and
-system time is false.
-
-
-More precisely: "The explanation is, that all time spent in processors
-other than the boot cpu is accounted as system time. If you time a
-program, add the user time and the system time, then you timing will be
-almost right, except for also including the system time that is
-correctly accounted for" (__Jakob Oslashstergaard__).
-
-
-This bug is corrected in 2.2 kernels.
-
-
-
-
-
-
-
-#
-
-
-
-
-
-
-
-
-
-
-
-!!3.3 SMP Programming
-
-
-
-Section by __Jakob Oslashstergaard__.
-
-
-This section is intended to outline what works, and what doesn't when
-it comes to programming multi-threaded software for SMP Linux.
-
-
-
-
-!Parallelization methods
-
-
-
-
-
-# POSIX Threads
-#
-
-# PVM / MPI Message Passing Libraries
-#
-
-# fork() -- Multiple processes
-#
-
-
-
-Since both fork() and PVM/MPI processes usually do not share memory,
-but either communicate by means of IPC or a messaging API, they will
-not be described further in this section. They are not very specific
-to SMP, since they are used just as much - or more - on uniprocessor
-computers, and clusters thereof.
-
-
-
-
-
-Only POSIX Threads provide us with multiple threads sharing ressources
-like - especially - memory. This is the thing that makes a SMP
-machine special, allowing many processors to share their memory. To
-use both (or more ;) processors of an SMP, use a kernel-thread
-library. A good library is the
-!LinuxThreads, a pthread library made by Xavier Leroy which is now
-integrated with glibc2 (aka libc6). Newer Linux distributions
-include this library by default, hence you do not have to
-obtain a separate package to use kernel threads.
-
-
-There are implementations of threads (and POSIX threads) that are
-application-level, and do not take advantage of the kernel-threading.
-These thread packages keep the threading in a single process,
-hence do not take advantage of SMP. However, they are good for
-many applications and tend to actually run faster than kernel-threads
-on single processor systems.
-
-
-Multi-threading has never been really popular in the UN*X world
-though. For some reason, applications requiring multiple processes or
-threads, have mostly been written using fork(). Therefore, when using
-the thread approach, one runs into problems of incompatible (not
-thread-ready) libraries, compilers, and debuggers. GNU/Linux is no
-exception to this. Hopefully the next few sections will sched a little
-light over what is currently possible, and what is not.
-
-
-
-
-
-
-
-!The C Library
-
-
-Older C libraries are not thread-safe. It is very important that you
-use GNU LibC (__glibc__), also known as __libc6__. Earlier
-versions are, of course possible to use, but it will cause you much more
-trouble than upgrading your system will, well probably :)
-
-
-If you want to use GDB to debug your programs, see below.
-
-
-
-
-!Languages, Compilers and debuggers
-
-
-There is a wealth of programming languages available for GNU/Linux,
-and many of them can be made to use threads one way or the other
-(some languages like Ada and Java even have threads as primitives in
-the language).
-
-
-This section will, however, currently only describe C and C++. If you
-have experience in SMP Programming with other languages, please
-enlighten us.
-
-
-GNU C and C++, as well as the EGCS C and C++ compilers work with the
-thread support from the standard C library (__glibc__). There are
-however a few issues:
-
-
-
-
-
-# When compiling C or C++, use the __-D_REENTRANT__ define
-in the compiler command line. This is necessary to make certain
-error-handling functions work like the errno variable.
-
-#
-
-# When using C++, If two threads throw exceptions concurrently, the
-program will segfault. The compiler does not generate thread-safe
-exception code.
-The workaround is to put a
-pthread_mutex_lock(&global_exception_lock) in the constructor(s) of
-every class you throw(), and to put the corresponding
-pthread_mutex_unlock(...) in the destructor. It's ugly, but it works.
-This solution was given by __Markus Ferch__.
-
-#
-
-
-
-The GNU Debugger __GDB__ as of version 4.18, should handle threads
-correctly. Most Linux distribution offer a patched, thread-aware gdb.
-
-
-It is not necessary to patch __glibc__ in any way just to make it
-work with threads. If you do not need to debug the software (this
-could be true for all machines that are not development workstations),
-there is no need to patch __glibc__.
-
-
-Note that core-dumps are of no use when using multiple
-threads. Somehow, the core dump is attached to one of the currently
-running threads, and not to the program as a whole. Therefore,
-whenever you are debugging anything, run it from the debugger.
-
-
-__Hint:__ If you have a thread running haywire, like eating 100%
-CPU time, and you cannot seem to figure out why, here is a nice way to
-find out what's going on: Run the program straight from the shell, no
-GDB. Make the thread go haywire. Use __top__ to get the PID of
-the process. Run GDB like __gdb program pid__. This will make
-GDB attach itself to the process with the PID you specified, and stop
-the thead. Now you have a GDB session with the offending thread, and
-can use __bt__ and the like to see what is happening.
-
-
-
-
-!Other libraries
-
-
-__!ElectricFence:__ This library is not thread safe. It should
-be possible, however, to make it work in SMP environments by inserting
-mutex locks in the !ElectricFence code.
-
-
-
-
-
-
-
-!Other points about SMP Programming
-
-
-
-
-
-# __Where can I found more information about parallel
-programming?__
-
-
-Look at the
-Linux Parallel Processing HOWTO
-
-Lots of useful information can be found at
-Parallel Processing using Linux
-
-Look also at the
-Linux Threads FAQ
-
-
-
-#
-
-# __Are there any threaded programs or libraries?__
-
-
-Yes. For programs, you should look at:
-Multithreaded programs on linux (I love hyperlinks, did
-you know that ? ;))
-
-
-As far as library are concerned, there are:
-
-
-
-
-; __OpenGL Mesa library__:
-
-Thanks to __David Buccarelli__,
-__Andreas Schiffler__ and __Emil Briggs__, it exists in a
-multithreaded version (right now [[1998-05-11], there is a working
-version that provides speedups of 5-30% on some OpenGL benchmarks). The
-multithreaded stuff is now included in the regular Mesa distribution as
-an experimental option. For more information, look at the
-Mesa library
-
-
-; __BLAS__:
-
-
-Pentium Pro Optimized BLAS and FFTs for Intel Linux
-
-Multithreaded BLAS routines are not available right now, but a dual proc
-library is planned for 1998-05-27, see
-Blas News for details.
-
-
-
-; __The GIMP__:
-
-__Emil Briggs__, the same guy who is involved in
-multithreaded Mesa, is also working on multithreaded The GIMP
-plugins. Look at
-http://nemo.physics.ncsu.edu/~briggs/gimp/index.html for more
-info.
-
-
-
-
-
-
-
-
-#
-
-
-
-
-
-
-
-
-
-
-----
-
-!!4. x86 architecture specific questions
-
-
-
-
-!!4.1 Why it doesn't work on my machine?
-
-
-
-
-
-
-# __Can I use my Cyrix/AMD/non-Intel CPU in SMP?__
-
-
-__Short answer:__ no.
-
-
-__Long answer:__ Intel claims ownership to the APIC SMP scheme, and
-unless a company licenses it from Intel they may not use it. There are
-currently no companies that have done so. (This of course can change in
-the future) FYI - Both Cyrix and AMD support the non-proprietary OpenPIC
-SMP standard but currently there are no motherboards that use it.
-
-
-
-
-#
-
-# __Why doesn't my old Compaq work?__
-
-
-Put it into MP1.1/1.4 compliant mode.
-
-
-check "Configure Hardware" -> "View / Edit details" -> "Advanced mode"
-(F7 I think) for a configuration option "APIC mode" and set this to
-"full Table mode". This is an official Compaq
-recommandation. (__Daniel Roesen__)
-
-
-(__Adrian Portelli__)To do this:
-
-
-## Press F10 when the server boots to enter the System Configuration Utility
-##
-
-## Press Enter to dismiss the splash screen
-##
-
-## Immediately press CTRL+A
-##
-
-## A message will appear informing you that you are now in "Advanced Mode"
-##
-
-## Then select "Configure Hardware" -> "View / Edit details"
-##
-
-## You will then see the advanced settings (intermixed with the ordinary ones)
-##
-
-## Stroll down to "APIC Mode" and then select "Fully Mapped"
-##
-
-## Save changes and reboot
-##
-
-
-
-
-
-#
-
-# __Why doesnt my ALR work?__
-
-
->From __Robert Hyatt__ : ALR Revolution quad-6 seems quite safe,
-while some older revolution quad machines without P6 processors seem
-"iffy"...
-
-
-
-
-#
-
-# __Why does SMP go so slowly?__ or __Why does one CPU show
-a very low bogomips value while the first one is normal?__
-
-
->From __Alan Cox__: If one of your CPU's is reporting a very low
-bogomips value the cache is not enabled on it. Your vendor probably
-provides a buggy BIOS. Get the patch to work around this or better yet
-send it back and buy a board from a competent supplier.
-
-
-A 2.0 kernel (> 2..36) contains the MTRR patch which should solve this
-problem (select option "Handle buggy SMP BIOSes with bad MTRR setup" in
-the "General setup" menu).
-
-
-I think buggy SMP BIOS handling is automatic in latest 2.2 kernels.
-
-
-
-
-#
-
-# __I've heard IBM machines have problems__
-
-
-Some IBM machines have the MP1.4 bios block in the EBDA, allowed but not
-supported below 2.2 kernels.
-
-
-There is an old 486SLC based IBM SMP box. Linux/SMP requires hardware
-FPU support.
-
-
-
-
-#
-
-# __Is there any advantage of Intel MP 1.4 over 1.1 specification?__
-
-
-Nope (according to Alan :) ), 1.4 is just a stricker specs of 1.1.
-
-
-
-
-#
-
-# __Why does the clock drift so rapidly when I run linux SMP?__
-
-
-
-This is known problem with IRQ handling and long kernel locks in
-the 2.0 series kernels. Consider upgrading to a later 2.2 kernel.
-
-
->From __Jakob Oestergaard__: Or, consider running xntpd. That should
-keep your clock right on time. (I think that I've heard that enabling
-RTC in the kernel also fixes the clock drift. It works for me! but I'm
-not sure whether that's general or I'm just being lucky)
-
-
-
-
-
-There are some kernel fixes in the later 2.2.x series that may
-fix this.
-
-
-
-
-
-
-
-#
-
-# __Why are my CPU's numbered 0 and 2 instead of 0 and 1 (or some other odd
-numbering)?__
-
-
-The CPU number is assigned by the MB manufacturer and doesn't mean
-anything. Ignore it.
-
-
-
-
-
-
-
-#
-
-# __My quad-Xeon system hangs as soon as it has decompressed the
-kernel__
-
-
-(__Doug Ledford__) Try recompiling LILO with LARGE_EBDA support
-and then making sure to always use make bzImage when compiling the
-kernel. That appears to have fixed the SMP boot hangs here on Intel
-multi-Xeon boards. However, please note that this also appears to break
-LILO in that the root= option no longer works, so make sure you rdev
-your kernel image at the same time you run lilo to make sure that the
-kernel loads the correct root filesystem at boot.
-
-
-(__Robert M. Hyatt__) With 3 cpus, do you have a terminator in the
-4th slot?
-
-
-
-
-#
-
-# __During boot machine hang signaling an IOAPIC problem__
-
-
-Try boot options "noapic" (__John Aldrich__) and/or "reboot=bios" (__Terry Shull__).
-
-
-
-
-#
-
-# __My system locks up during heavy NFS traffic__
-
-
-Try the later 2.2.x kernels and the knfsd patches. This is
-currently under investigation. (__Wade Hampton__)
-
-
-
-
-
-
-
-#
-
-# __My system locks up with no oops messages__
-
-
-If you are using kernels 2.2.11 or 2.2.12, get the latest kernel. For
-example 2.2.13 has a number of SMP fixes. Several people have reported
-these kernels to be unstable for SMP. These same kernels may have NFS
-problems that can cause lockups. Also, use a serial console to capture
-your oops messages. (__Wade Hampton__)
-
-
-If the problem remains (and the other suggestions on this list didn't
-help either), then you could try the latest 2.3 kernels. They have more
-verbose (and more robust) SMP/APIC code, and automatic
-hard-lockup-prevention code which will produce meaningful oopses instead
-of a silent hang. (__Ingo Molnar__)
-
-
-(__Osamu Aoki__) You MUST also ''disable'' all BIOS related
-power save features. Example of good configuration (Dual Celeron 466
-Abit BP6):
-----
-
-POWER MANAGEMENT SETUP.
-ACPI: Disabled
-POWER MANAGEMENT: Disabled
-PM CONTROL by APM: No
-
-----
-If power management features are activated, some random freeze can occur.
-
-
-
-
-#
-
-# __Debugging lockups__
-
-
-(item by __Wade Hampton__)
-
-
-A good means of debugging lockups is to get the ikd patch from
-Andrea Arcangeli:
-ftp://ftp.suse.com/pub/people/andrea/kernel-patches
-
-There are several of debug options, but do NOT use the
-soft lockup option! For newer SMP boxes,
-turn kernel debugging then turn on the NMI oopser.
-To verify that the NMI oopser is working, after booting the
-new kernel,
-/cat /proc/interrupts and verify that you are getting
-NMIs. When the box locks up, you should get an OOPS.
-
-
-You may also try the %eip option. This allows the kernel
-to print on the console the %eip address every time a kernel function
-is called. When the box locks up, write down the first column
-ordered by the second column then lookup the addresses in the
-System.map file. This works only in console mode.
-
-
-Also note that the use of a serial console can greatly facilitate
-debugging kernel lockups, not just SMP kernel lockups!
-
-
-
-
-#
-
-# __"APIC error interrupt on CPU#n, should never happen" messages
-in logs__
-
-
-A message like:
-----
-
-APIC error interrupt on CPU#, should never happen.
-... APIC ESR0: 00000002
-... APIC ESR1: 00000000
-
-----
-indicates a 'receive checksum error'. This cannot be caused by Linux as
-the APIC message checksumming part is completely in hardware. It might
-be marginal hardware. As long as you dont see any instability, they are
-not a problem - APIC messages are retried until delivered. (__Ingo
-Molnar__)
-
-
-
-
-#
-
-
-
-
-
-
-
-
-!!4.2 Possible causes of crash
-
-
-
-In this section you'll find some __possible__ reasons for a crash
-of an SMP machine (credits are due to __Jakob Oslashstergaard__ for
-this part). As far as I (David) know, theses problems are Intel
-specific.
-
-
-
-
-
-
-
-
-* __Cooling problems__
-
-
->From __Ralf Baumlchle__: [[Related to case size and fans]
-It's important that the air is flowing. It of course can't where cables
-etc. are preventing this like in too small cases. On the other side
-I've seen oversized cases causing big problems. There are some tower
-cases on the market that actually are worse for cooling than desktops.
-In short, the right thing is thinking about aerodynamics in the case.
-Extra cases for hot peripherals are usefull as well.
-
-
-Of course you can always go to Radio Shack (or similar) and get another fan.
-You can use the lm_sensors to monitor the CPU temperature of newer PII
-and PIII processors. This might help you to determine if heat is
-a problem. (__Wade Hampton__)
-
-
-
-
-
-
-
-*
-
-* __Bad memory__
-
-
-Don't buy cheap RAM and don't use mixed RAM modules on a motherboard
-that is picky about it.
-
-
-Especially Tyan motherboards are known to be picky about RAM speed.
-
-
-
-
-
-There have been some report of 10ns PC100 RAM being sold with
-motherboards where the CPU really needs 8ns RAM. (__Wade Hampton__)
-
-
-
-
-
-
-
-*
-
-* __Bad combination of different stepping CPUs__
-
-
-Check /proc/cpuinfo to see that your CPUs are same stepping.
-
-
-
-
-*
-
-* __If your system is unstable, then DON'T overclock it!__
-
-
-...and even if it is stable, DON'T overclock.
-
-
->From __Ralf Baumlchle__: Overclocking causes very subtle
-problems. I have a nice example, one of my overclocked old machines
-misscomputes a couple of pixels of a 640 x 400 fractal. The problem is
-only visible when comparing them using tools. So better say ''never,
-nuncas, jamais, niemals'' overclock.
-
-
-
-
-
-
-
-*
-
-* __2..x kernel and fast ethernet__ (from __Robert G. Brown__)
-
-
-2..x kernels on high performance fast ethernet systems have significant
-(and known) problems with a race/deadlock condition in the networking
-interrupt handler.
-
-
-The solution is to get the latest 100BT development drivers from
-CESDIS Linux Ethernet device drivers site (ones that define
-SMPCHECK).
-
-
-
-
-*
-
-* __A bug in the 440FX chipset__ (from __Emil Briggs__)
-
-
-If you had a system using the 440FX chipset then your problem with the
-lockups was possibly due to a documented errata in the chipset. Here is
-a reference
-
-
-References:
-Intel 440FX PCIset 82441FX (PMC) and 82442FX (DBX) Specification Update.
-pg. 13
-
-
-
-http://www.intel.com/design/pcisets/specupdt/297654.htm
-
-The problem can be fixed with a BIOS workaround (Or a kernel patch) and
-in fact David Wragg wrote a patch that's included with Richard Gooch's
-MTTR patch. For more information and a fix look here:
-
-
-
-http://nemo.physics.ncsu.edu/~briggs/vfix.html
-
-
-
-*
-
-* __DONT run emm386.exe before booting linux SMP__
-
-
->From __Mark Duguid__, dumb rule #1 with W6LI
-motherboards. ;)
-
-
-
-
-*
-
-* __If the machine reboots/freezes after a while, there can be two good
-BIOS + memory related reasons__ (from __Jakob Oslashstergaard__)
-
-
-** If the BIOS has settings like "memory hole at 16M" and/or
-"OS/2 memory > 64MB", try disabling them both. Linux does
-not always react well with theese options.
-**
-
-** If you have more than 64 MB of memory in the machine, and you
-specified the exact number manually in the LILO configuration,
-you should specify one MB less than you actually have in the
-machine. If you have 128 MB, you lilo.conf line looks like:
-append="mem=127M"
-**
-
-
-*
-
-* __Be aware of IRQ related problems__
-
-
-Sometime, some cards are not recognized or can trigger IRQ
-conflicts. Try shuffling cards on slots in different ways and
-possibly moving them to different IRQs.
-
-
-Contributed by __hASCII__ : removing an " append="hisax=9,2,3""
-line in lilo.conf allowed using a kernel from the 2.1.xx series with
-activated ISDN + Hisax support. Kernels from the 2..xx series doesn't
-make problems like this.
-
-
-Try also to set BIOS setup option like "MP 1.4 mode" or "route PCI
-interrupts through IOAPIC", or "OS Type" not set to DOS neither
-Novell (__Ingo Molnar__).
-
-
-
-
-
-
-
-*
-
-* __Floppy access while sound is active__
-
-
-If you lockup when trying to access the floppy (for example
-while sound is playing) you may have to edit drivers/pci/quirks.c
-and set /int isa_dma_bridge_buggy = 1;
-This is a problem with my Dell WS400 dual PII/300, 2.2.x, SMP
-(__Wade Hampton__).
-
-
-
-
-*
-
-
-
-
-
-
-
-
-!!4.3 Motherboard specific information
-
-
-
-''Please note'': Some more specific information can be found with
-the list of
-Motherboards rumored to run Linux SMP
-
-
-
-!Motherboards with known problems
-
-
-
-
-
-* none right now
-*
-
-
-
-
-
-
-
-
-!!4.4 Low cost SMP Linux box (dual Celeron box)
-
-
-
-(__Steacutephane Eacutecolivet__)
-
-
-
-
-
-The lowest cost SMP Linux boxes with nowadays buyable processors are
-dual Celeron systems. Such a system is not officially possible
-according to Intel. Better think about the second generation of
-Celeron, those with 128 Kb L2 cache.
-
-
-
-
-!Is it possible to run a dual Intel Celeron box ?
-
-
-__Official answer from Intel:__ no, Celeron cannot work in SMP mode.
-
-
-__Practical answer:__ it is possible, but requires hardware
-alteration for Slot 1 processors. Alteration is described by Tomohiro
-Kawada on his
-Dual Celeron System page. Of
-course, this kind of modification removes warranties... Some versions
-of Celeron processor are also available in Socket 370 format. In that
-case, alteration may just be done on the Socket 370 to Slot 1 adapter or
-may even be sold pre-wired for SMP use. (__Andy Poling__, __Hans
-- Erik Skyttberg__, __James Beard__)
-
-
-There is also a motherboard (ABIT BP6) allowing two Celerons in Socket
-370 format to be inserted (__Martijn Kruithof__, __Ryan
-!McCue__). ABIT Computer BP6 verified tested and native to linux with
-dual ppga socket 370 (__Andre Hedrick__).
-
-
-
-
-!How does Linux behave on a dual Celeron system ?
-
-
-Fine, thank you.
-
-
-
-
-!Celeron processors are known to be easily overclockable. And dualCeleron system ?
-
-
-It __may__ work. However, overclocking this kind of system is not
-as easy as overclocking a mono-processor one. It is definitly not a good
-idea for a production system. For personal use, dual Celeron 300A
-systems running rock-solid at 450 MHz have been reported. (__numerous
-people__)
-
-
-
-
-!And making a quad Celeron system ?
-
-
-It is impossible. Celeron processors have nearly the same features as
-basic Pentium II chips. If you want more than 2 processors in your
-system, you'll have to look at Pentium Pro, Pentium II Xeon or Pentium
-III (?) boxes.
-
-
-
-
-
-
-
-!What about mixing Celeron and Pentium II processor ?
-
-
-A system using a "re-enable" Celeron processor and a Pentium II
-processor with the same steppings __may theorically__ work.
-
-
-__Alexandre Charbey__ as made such a system:
-
-
-* Asus P2B-D motherboard, proc 1: Celeron 366, proc 2: Pentium II
-400@266
-*
-
-* 66Mhz and 75Mhz bus frenquencies where functionnal
-*
-
-* the fastest processor (in this case the Celeron) should be put on
-the second slot. Swapping processors (fatest first) leads to quick
-failure.
-*
-
-
-
-
-----
-
-!!5. Sparc architecture specific questions
-
-
-
-
-
-
-
-!!5.1 Which Sparc machines are supported ?
-
-
-
-Quoting the
-!UltraLinux web
-page (only SMP systems):
-
-
-* UltraSPARC PCI based workstations: Ultra60, Ultra450
-*
-
-* UltraSPARC SBUS based servers: Enterprise 1, 2, 150
-*
-
-* UltraSPARC SBUS based large servers: Enterprise 3000, 4000, 5000, 6000, 10000
-*
-
-* UltraSPARC PCI based servers: Enterprise 250, 450
-*
-
-* SPARC sun4m SMP machines (__Anton Blanchard__)
-*
-
-*
-Starfire E10000
-*
-
-
-
-!UltraLinux has ran on a 14 CPUs machine (see the
-dmesg output) and on a
-Starfire E10000 with 24 CPUs (see the
-dmesg output).
-
-
-
-
-!!5.2 Specific problem related to Sparc SMP support
-
-
-
-(__David Miller__)
-There should not be any worries.
-
-
-The only known problem, and one we don't intend to fix, is that if you
-build an SMP kernel for 32-bit (ie. non-ultrasparc) systems, this kernel
-will not work on sun4c systems.
-
-
-
-
-!!5.3 SMP specific limit with current kernel (2.2)
-
-
-
-(__David Miller__) There is a bug in the include/linux/tasks.h
-header file, it needs to define NR_CPUS to 64 on !UltraSparc as this is
-the upper limit for the hardware we support :-)
-
-
-
-----
-
-!!6. PowerPC architecture specific questions
-
-
-
-
-
-
-
-!!6.1 Which PPC machines are supported ?
-
-
-
-
-
-
-* !PowerSurge boards (including UMAX s900)
-*
-
-* !PowerMac
-*
-
-* Motorola MTX: support under developement. Patches not yet
-integrated into the main kernel (__Troy Benjegerdes__)
-*
-
-
-
-(__Cort Dougan__) Not supported: PPC RS/6000 systems
-
-
-
-
-
-
-
-!!6.2 Specific problem related to PPC SMP support
-
-
-
-Nothing. Usual SMP compiling (see above). As usual, be aware, modules
-are specific either for UP or SMP. Recompile them. (__Paul
-Mackerras__)
-
-
-
-----
-
-!!7. Alpha architecture specific questions
-
-
-
-
-
-
-
-!!7.1 Which Alpha machines are supported ?
-
-
-
-(__Geerten Kuiper__) SMP works for most, if not all, AXP servers.
-
-
-(__Jay A Estabrook__) SMP does seem to work on most of our [[Compaq]
-boxes with 2 or more CPUs. That includes :
-
-
-* AS2000/2100 (SABLE)
-*
-
-* AS4000/4100 (RAWHIDE)
-*
-
-* DS20 (DP264)
-*
-
-* GS320 (see the
-bootlog for a 31 CPUs machine)
-*
-
-
-
-It does not include :
-
-
-* AS2100A (LYNX)
-*
-
-* !TurboLaser bigboys (8200/8400)
-*
-
-
-
-(__Alpha Processor Inc__) SMP support has been qualified for all API
-SMP systems starting from later 2.2-series kernels (approximately kernel
-2.2.7).
-At the time of writing, that is :
-
-
-* DP264
-*
-
-* UP2000
-*
-
-See
-API's support website for more info.
-
-
-
-
-!!7.2 Specific problem related to Alpha SMP support
-
-
-
-None (really ? :-)
-
-
-
-
-
-
-----
-
-!!8. Useful pointers
-
-
-
-
-!!8.1 Various
-
-
-
-
-
-
-*
-Parallel Processing using Linux
-
-*
-
-*
-Linux Parallel Processing HOWTO
-
-*
-
-* __(outdated)__
-Linux SMP home page
-
-*
-
-* linux-smp mailing list
-
-
-To __subscribe__, send subscribe linux-smp in the message body
-at
-majordomo@vger.kernel.org
-
-To __unsubscribe__, send unsubscribe linux-smp in the message body at
-majordomo@vger.kernel.org
-
-
-Linux SMP archives
-
-
-Linux SMP archives at progressive-comp.com
-
-
-
-
-
-
-*
-
-*
-pthread library made by Xavier Leroy
-
-*
-
-*
-Motherboards rumored to run Linux SMP
-
-*
-
-*
-procps
-
-*
-
-*
-procps patch for 2.2.x
-
-*
-
-*
-xosview
-
-*
-
-*
-xosview for 2.2.x
-
-*
-
-*
-SMP Performance of Linux
-
-*
-
-*
-CESDIS Linux Ethernet device drivers site
-
-*
-
-*
-Dual Celeron System
-
-*
-
-
-
-
-
-
-
-
-!!8.2 Multithreaded programs and library
-
-
-
-
-
-
-*
-Linux Threads FAQ
-
-*
-
-*
-Multithreaded programs on linux
-
-*
-
-*
-Pentium Pro Optimized BLAS and FFTs for Intel Linux (not available right now,
-but a dual proc library is planned for 5/27/98, see
-Blas News for details)
-
-*
-
-*
-Mesa library (with experimental
-multi-threading)
-
-*
-
-*
-Parallel plugins for The GIMP
-
-*
-
-
-
-
-
-
-
-
-
-
-
-!!8.3 SMP specific patches
-
-
-
-
-
-
-*
-Patch for a bug in the 440FX chipset
-
-*
-
-*
-PSET - Processor Sets for the Linux kernel
-
-*
-
-*
-Ingo Molnar SMP patches (for experts only, please read
-linux-smp@vger.kernel.org)
-
-*
-
-
-
-
-
-
-
-
-
-
-
-!!8.4 Parallelizing/Optimizing Compilers for 586/686 machines
-(__Sumit Roy__)
-
-
-
-
-
-*
-Pentium Compiler Group creators of pgcc
-
-*
-
-*
-Absoft , Fortran 90 and
-Fortran 77 compilers
-
-*
-
-*
-The Portland Group, Inc., supports the
-OpenMP standard for Fortran parallelization on
-Linux
-
-*
-
-*
-Pacific-Sierra Research Corporation, has a free F90 compiler for Linux, as well
-as parallelizing compilers for SMP Linux
-
-*
-
-*
-Applied Parallel Research, currently have parallelizing
-compilers for WinNT
-
-*
-
-*
-KAI has a C++-Compiler for
-Linux, that understands OpenMPI. It is called Guide_OpenMP. Info
-under
-http://www.kai.com/parallel/kappro/guide. (__Gero Wedemann__)
-
-*
-
-
-
-
-
-
-
-----
-
-!!9. Glossary
-
-!!9.1 Definitions
-
-
-
-
-
-
-* __SMP__ Symmetric Multi-Processors.
-
-*
-
-* __UP__ Uni-Processor: system with one processor.
-
-*
-
-* __APIC__ Advanced Programmable Interrupt Controler.
-
-*
-
-* __thread__ A thread is a processor activity in a
-process. The same process can have multiple threads. Those threads share
-the process address space and can therefore share data.
-
-*
-
-* __pthread__ Posix thread, threads defined by the Posix
-standard.
-
-*
-
-* __process__ Program in execution, with its environment.
-
-*
-
-* __MTRR__ Memory Type Range Register
-
-*
-
-* __APM__ Advanced Power Management.
-
-*
-
-* __FPU__ Floating Point Unit. Also called arithmetic
-co-processor.
-
-*
-
-* __IRQ__ Interrupt !ReQuest.
-
-*
-
-* __EBDA__ ??
-
-*
-
-* __oops__ Internal kernel error.
-
-*
-
-* __Cluster__ Group of computers that achieve a common
-computation (also known as Beowulf within the Linux community).
-
-*
-
-
-
-
-
-!!9.2 Concepts
-
-
-
-
-
-
-* __Data Races__
-
-
-A data race happens when to processes want to modify a shared variable
-concurrently without protecting themselves from the effect of the other
-process.
-
-
-Let A a shared variable. Let P1 and P2 two processes that access this
-variable. Those two processes are making the same following operation:
-"read A in tmp variable (local to the precess); do tmp = tmp + 1 ; write
-tmp in A". If the A variable is not protected by a lock, resulting
-executions could not correspond to what is espected. For example, here
-is two examples if one do not lock A:
-
-case #1:
-A=
-P1: read A -> tmp1 (so tmp1 is )
-P2: read A -> tmp2 (so tmp2 is )
-P1: tmp1 = tmp1 + 1 (so tmp1 is 1)
-P2: tmp2 = tmp2 + 1 (so tmp2 is 1)
-P1: tmp1 -> write A (so A is 1)
-P2: tmp2 -> write A (so A is 1)
-
-
-
-
-
-case #2:
-A=
-P1: read A -> tmp1 (so tmp1 is )
-P1: tmp1 = tmp1 + 1 (so tmp1 is 1)
-P1: tmp1 -> write A (so A is 1)
-P2: read A -> tmp2 (so tmp2 is 1)
-P2: tmp2 = tmp2 + 1 (so tmp2 is 2)
-P2: tmp2 -> write A (so A is 2)
-
-
-
-To avoid this kind of problem, one uses a lock:
-
-A=:
-P1: lock A
-P1: read A -> tmp1 (so tmp1 is )
-P2: lock A (so P2 is blocked)
-P1: tmp1 = tmp1 + 1 (so tmp1 is 1)
-P1: tmp1 -> write A (so A is 1)
-P1: unlock A (so P2 is unblocked)
-P2: read A -> tmp2 (so tmp2 is 1)
-P2: tmp2 = tmp2 + 1 (so tmp2 is 2)
-P2: tmp2 -> write A (so A is 2)
-P2: unlock A
-
-
-
-
-
-*
-
-* __Deadlock__
-
-
-This is an inter-blocking that occurs when two processes want to access
-at shared variables mutually locked. For example, let A and B two locks
-and P1 and P2 two processes:
-
-
-
-
-P1: lock A
-P2: lock B
-P1: lock B (so P1 is blocked by P2)
-P2: lock A (so P2 is blocked by P1)
-
-Process P1 is blocked because it is waiting for the unlocking of B
-variable by P2. However P2 also needs the A variable to finish its
-computation and free B. So we have a deadlock.
-
-
-In this example, the problem is very simple. But imagine what can happen
-in a 2 millions of lines of code (like the linux kernel) with hundreds
-of locks. :-)
-
-*
-
-
-
-
-
-
-
-
-
-
-----
-
-!!10. What's new ?
-
-
-
-
-
-
-
-; __v1.12.1, 25 october 2000__:
-
-
-
-
-* Put all authors in Bryant, Hartner, Qi and Venkitachalam paper
-*
-
-
-
-
-; __v1.12, 22 october 2000__:
-
-
-
-
-* Explanation on why not trust Xosview on scheduling (__Rik van Riel__)
-*
-
-* A pointer to an article that compares 2.2 and 2.4 kernels (__Ray Bryant__)
-*
-
-
-
-
-; __v1.11, 8 october 2000__:
-
-
-
-
-* Linux boots on a Sun E1000 with 24 CPUs
-*
-
-* Linux boots on a !AlphaServer with 31 CPUs
-*
-
-
-
-
-; __v1.10, 5 october 2000__:
-
-
-
-
-* New linux-smp mailing-list adress : linux-smp@vger.kernel.org
-(me)
-*
-
-* Tell where to find RTC setting in kernel config (__Patrick
-Doyle__)
-*
-
-* glossary updated and concepts added (from a french version made
-by __Ludovic Danigo__)
-*
-
-* Fixed an inconsistency (__Matthias Schniedermeyer__)
-*
-
-* Deleted wrong links (__Johan Ekenberg__)
-*
-
-
-
-
-; __v1.9.1, 28 September 2000__:
-
-
-
-
-* updated with a submission from __Stig Telfer__ detailing SMP support
-on API Alpha systems
-*
-
-
-
-
-
-
-
-; __v1.9, 13 january 2000__:
-
-
-
-
-* Remember to disable all BIOS power-save features (__Osamu
-Aoki__)
-*
-
-* Explain how to access to Compaq server into advanced
-configuration mode (__Adrian Portelli__)
-*
-
-
-
-
-; __v1.8, 8 november 1999__:
-
-
-
-
-* quad-celeron motherboard was a hoax, restored old paragraph
-(__Simen Timian Thoresen__)
-*
-
-
-
-
-; __v1.7, 6 november 1999__:
-
-
-
-
-* new introduction (__C. Polisher__ aka cp)
-*
-
-* numerous typo and grammatical fixes (cp)
-*
-
-* introductory paragraph on kernel compilation (cp)
-*
-
-* introductory paragraph on SMP need (cp)
-*
-
-* reference on KAI optimizing compiler (__Gero Wedemann__)
-*
-
-* quad-celeron motherboard exists (__Jeffrey H. Ingber__)
-*
-
-
-
-
-; __v1.6, 21 october 1999__:
-
-
-
-
-* added information on xosview scheduling perturbation
-*
-
-* added "APIC error interrupt on CPU#n" message information
-*
-
-* added information on hard lockup
-*
-
-* deleted section "How to optain maximum performance" (was
-obsolete)
-*
-
-* added info on dual systems with different x86 procs (a Celeron
-and a P-II)
-*
-
-
-
-
-; __v1.5, 4 october 1999__:
-
-
-
-
-* more precision in PSET description
-*
-
-
-
-
-; __v1.4, 30 september 1999__:
-
-
-
-
-* precize to enable MTRR support for an x86 SMP kernel (me)
-*
-
-
-
-
-; __v1.3, 29 september 1999__:
-
-
-
-
-* many many grammar and typographical fixes (__Wade Hampton__
-aka hww)
-*
-
-* added info in short introduction related to 2.2/2.4/2.0 diffs (hww)
-*
-
-* added step by step things to do to recompile a kernel (hww and me)
-*
-
-* added info related to SMP/UP modules problems (hww)
-*
-
-* added precision in Posix Threads section related to user (hww)
-vs. kernel threads (hww)
-*
-
-* new item about NFS and kernel lock (hww)
-*
-
-* new item about kernel lock without message (hww)
-*
-
-* new item about debugging lockup problems (hww)
-*
-
-* added info about heating problems (hww)
-*
-
-* miscellaneous updates I've forget about (hww)
-*
-
-* new item about floppy access and sound (hww)
-*
-
-
-
-
-; __v1.2, 27 septembre 1999__:
-
-
-
-
-* name change: this document is now a HOWTO. TWD, and fast! (__Guylhem Aznar__)
-*
-
-
-
-
-; __v1.1, 26 septembre 1999__:
-
-
-
-
-* added a link to first Chris Pirih FAQ draft
-*
-
-* expanted an IRQ related problems
-*
-
-
-
-
-; __v1.00, 25 septembre 1999__:
-
-
-
-
-* first upgrade in a long long time!
-*
-
-* reprocessed the whole FAQ: 2.2 is here and 2.4 soon
-*
-
-* added kernel locking information from Ingo Molnar
-*
-
-* deleted item "How will my application perform under SMP?": outdated
-*
-
-* deleted item "My SMP system is locking up all the time.":
-outdated
-*
-
-* deleted item "You are running 2..35 aren't you ?": outdated
-*
-
-* deleted item "Some hardware is also known to cause problems.":
-outdated
-*
-
-* blanked section "Motherboards with known problems". We should
-restart from scratch
-*
-
-* deleted section "Motherboards with NO known problems": outdated
-*
-
-* updated dual celeron section (numerous people)
-*
-
-* added "SPARC sun4m SMP machines" to supported SMP sparc machines
-(__Anton Blanchard__)
-*
-
-* added a "During boot machine hang signaling an IOAPIC problem"
-item in "Why it doesn't work on my machine?" section
-*
-
-* added a "What about SMP performances?" item
-*
-
-* updated "Why doesn't my old Compaq work?" item
-*
-
-* fixed an outdated pointer
-*
-
-* added a pointer to Ingo test SMP patches
-*
-
-
-
-
-; __v0.54, 13 march 1999__:
-
-
-
-
-* Added a section about SMP Alpha systems
-*
-
-
-
-
-; __v0.53, 08 march 1999__:
-
-
-
-
-* Added a section about SMP PowerPC systems
-*
-
-
-
-
-; __v0.52, 07 march 1999__:
-
-
-
-
-* Added a section about SMP Sparc systems
-*
-
-
-
-
-; __v0.51, 06 march 1999__:
-
-
-
-
-* Added a dual-celeron section
-*
-
-* Deleted Adaptec section
-*
-
-* Updated procps link
-*
-
-* Updated xosview link
-*
-
-* Added an answer for quad Xeon boot hang
-*
-
-* Updated item about glibc patch for gd: should be included in RH 5.2
-*
-
-
-
-
-; __v0.50, 03 february 1999__:
-
-
-
-
-* Updated "Multithreaded programs on linux" link
-*
-
-
-
-
-; __v0.49, 13 january 1999__:
-
-
-
-
-* Update about CONFIG_SMP. Added .txt to
-Documentation/smp. (__Michael Elizabeth Chastain__)
-*
-
-
-
-
-; __v0.48, 10 december 1998__:
-
-
-
-
-* Mispelled corrected. Email address corrected.
-*
-
-
-
-
-; __v0.47, 20 november 1998__:
-
-
-
-
-* Added that 2..36 as the MTRR patch (related to the !BogoMips problem)
-*
-
-
-
-
-; __v0.46, 10 november 1998__:
-
-
-
-
-* Update about Epox KP6-LS motherboards
-*
-
-
-
-
-; __v0.45, 25 october 1998__:
-
-
-
-
-* Corrected an error regarding /proc/stat file
-*
-
-* Added a pointer to CESDIS Ethernet Linux Drivers site
-*
-
-
-
-
-; __v0.44, 14 october 1998__:
-
-
-
-
-* Updated the link to the web page: ''Motherboards rumored to run
-Linux SMP''
-*
-
-* Added Jakob explanation how to time SMP systems with 2.0 kernels
-*
-
-
-
-
-; __v0.43, 9 september 1998__:
-
-
-
-
-* Updated first question in section 3.1
-*
-
-* Updated mt-Mesa link: multi-threaded is now included as
-experimental in the Mesa distribution
-*
-
-
-
-
-; __v0.42, 2 september 1998__:
-
-
-
-
-* Minor cosmetic update in sect 3.3
-*
-
-* Two links (multithreaded Mesa and SMP performance) marked
-outdated
-*
-
-* Updated the item about threads and exceptions in C++ (sect 3.3)
-*
-
-
-
-
-; __v0.41, 1 september 1998__:
-
-
-
-
-* Added a major section: "3.3 SMP Programming" written by Jakob
-Oslashstergaard
-*
-
-* moved some item of section "3.2 User side" in sect 3.3
-*
-
-
-
-
-; __v0.40, 27 august 1998__:
-
-
-
-
-* Updated section 3.1, item 7: processor affinity
-*
-
-
-
-
-; __v0.39, 27 august 1998__:
-
-
-
-
-* Updated needed Award BIOS version for Tyan motherboards
-(__hASCII__)
-*
-
-* Added an item on IRQ in the crash section (me and
-__hASCII__)
-*
-
-* Added good support of Asus P2B-DS (__Ulf Rompe__)
-*
-
-* Added another smp-list archive in pointer section (__Hank Leininger__)
-*
-
-
-
-
-; __v0.38, 8 august 1998__:
-
-
-
-
-* Added a pointer to the Linux Threads FAQ
-*
-
-
-
-
-; __v0.37, 30 July 1998__:
-
-
-
-
-* __Emil Briggs__ is working on parallel plugins for Gimp (see
-"Is there any threaded programs or library?", sect. "User side")
-*
-
-
-
-
-; __v0.36, 26 July 1998__:
-
-
-
-
-* Thanks to __Jakob Oslashstergaard__, two changes in "Possible
-causes of Crash"
-
-
-** Changed 2..33 to 2..35 (latest stable)
-**
-
-** Added a "BIOS related causes of failure"
-**
-
-
-*
-
-
-
-
-; __v0.35, 14 July 1998__:
-
-
-
-
-* Added N440BX Server Board in Motherboards with NO problems
-*
-
-* Added a succes story for !GigaByte motherboard with BIOS upgrade
-*
-
-* Added a "How to obtain maximum performance ?" section (waiting
-for your contributions ;)
-*
-
-
-
-
-; __v0.34, 10 june 1998__:
-
-
-
-
-* Added a "Parallelizing/Optimizing Compilers for 586/686 machines"
-section in section "Useful Pointers", thanks to __Sumit Roy__
-*
-
-* Corrected a mispelling, "Asus P/I-UP5" is in fact "Asus
-P/I-P65UP5"
-*
-
-
-
-
-; __v0.33, 3 june 1998__:
-
-
-
-
-* Yet another success story for a !GigaByte DLX Motherboard.
-*
-
-* A tip for Tyan motherboards, disable the "DRAM Fast Leadoff" BIOS
-option
-*
-
-
-
-
-; __v0.32, 27 may 1998__:
-
-
-
-
-* Asus P/I-UP5 added in the motherboard-with-NO-problem section
-*
-
-
-
-
-; __v0.31, 18 may 1998__:
-
-
-
-
-* Elitegroup P6LX2-A works with 2.1.100 and 101
-*
-
-* Bugs should be reported to linux-smp@vger.rutgers.edu
-*
-
-
-
-
-; __v0.30, 12 may 1998__:
-
-
-
-
-* !SuperMicro is now in the motherboard-with-NO-problem section
-*
-
-
-
-
-; __v0.29, 11 may 1998__:
-
-
-
-
-* A success story for a !GigaByte 686 motherboard with 2.1.101
-*
-
-* Added a new item in the "User Side" section: "Is there any
-threaded programs or library?"
-*
-
-* OpenGL Mesa library is beeing multithreaded. Cool! See the new
-section for details.
-*
-
-
-
-
-; __v0.28, 09 may 1998__:
-
-
-
-
-* A US mirror of this FAQ is now available (see Introduction)
-*
-
-* Merge of the two confusing Gigabyte 686 entries
-*
-
-
-
-
-; __v0.27, 05 may 1998__:
-
-
-
-
-* New info for the Adaptec and !TekRam drivers
-*
-
-* Micronics W6-LI motherboard works under SMP
-*
-
-
-
-
-
-
-
-
-
-
-
-----
-
-!!11. List of contributors
-
-
-Many thanks to those who help me to maintain this HOWTO:
-
-
-
-
-
-# Tigran A. Aivazian
-#
-
-# John Aldrich
-#
-
-# Niels Ammerlaan
-#
-
-# H. Peter Anvin
-#
-
-# Osamu Aoki
-#
-
-# Guylhem Aznar
-#
-
-# Ralf Baumlchle
-#
-
-# James Beard
-#
-
-# Troy Benjegerdes
-#
-
-# Anton Blanchard
-#
-
-# Emil Briggs
-#
-
-# Robert G. Brown
-#
-
-# Ray Bryant
-#
-
-# Alexandre Charbey
-#
-
-# Michael Elizabeth Chastain
-#
-
-# Samuel S. Chessman
-#
-
-# Alan Cox
-#
-
-# Andrew Crane
-#
-
-# Cort Dougan
-#
-
-# Patrick Doyle
-#
-
-# Mark Duguid
-#
-
-# Steacutephane Eacutecolivet
-#
-
-# Johan Ekenberg
-#
-
-# Jocelyne Erhel
-#
-
-# Jay A Estabrook
-#
-
-# Byron Faber
-#
-
-# Mark Garlanger
-#
-
-# hASCII
-#
-
-# Wade Hampton
-#
-
-# Andre Hedrick
-#
-
-# Claus-Justus Heine
-#
-
-# Benedikt Heinen
-#
-
-# Florian Hinzmann
-#
-
-# Moni Hollmann
-#
-
-# Robert M. Hyatt
-#
-
-# Jeffrey H. Ingber
-#
-
-# Richard Jelinek
-#
-
-# Tony Kocurko
-#
-
-# Geerten Kuiper
-#
-
-# Martijn Kruithof
-#
-
-# Doug Ledford
-#
-
-# Kumsup Lee
-#
-
-# Hank Leininger
-#
-
-# Ryan !McCue
-#
-
-# Paul Mackerras
-#
-
-# Cameron !MacKinnon
-#
-
-# Joel Marchand
-#
-
-# David Maslen
-#
-
-# Chris Mauritz
-#
-
-# Jean-Francois Micouleau
-#
-
-# David Miller
-#
-
-# Ingo Molnar
-#
-
-# Ulf Nielsen
-#
-
-# Jakob Oestergaard
-#
-
-# C Polisher
-#
-
-# Adrian Portelli
-#
-
-# Matt Ranney
-#
-
-# Daniel Roesen
-#
-
-# Ulf Rompe
-#
-
-# Jean-Michel Rouet
-#
-
-# Volker Reichelt
-#
-
-# Sean Reifschneider
-#
-
-# Rik van Riel
-#
-
-# Sumit Roy
-#
-
-# Thomas Schenk
-#
-
-# Matthias Schniedermeyer
-#
-
-# Terry Shull
-#
-
-# Chris K. Skinner
-#
-
-# Hans - Erik Skyttberg
-#
-
-# Szakacsits Szabolcs
-#
-
-# Jukka Tainio
-#
-
-# Stig Telfer
-#
-
-# Simen Timian Thoresen
-#
-
-# El Warren
-#
-
-# Gregory R. Warnes
-#
-
-# Gero Wedemann
-#
-
-# Christopher Allen Wing
-#
-
-# Leonard N
. Zubkoff
-#
-
-
-
-
-----
+Describe
[HowToSMPHOWTO
] here.
