LINUXGAMES

WARNING – AMD CPU Bug

January 21st, 2002 by Crusader

Gentoo Linux’s site posted a warning forowners of recent AMD CPUs (Athlon/Duron): there’s anextended paging memory corruption bug encountered when AGP is in use:

And, this problem hits us because Linux 2.4 kernels compiled with a Pentium-Classic or higher Processor family kernel configuration setting will automatically take advantage of extended paging (for kernel hackers out there, this is the X86_FEATURE_PSE constant defined in include/asm-i386/cpufeature.h.) Fortunately, there is a quick and easy fix for this problem. If you have been experiencing lockups on your Athlon, Duron or Athlon MP system when using AGP video, try passing the mem=nopentium option to your kernel (using GRUB or LILO) at boot-time. This tells Linux to go back to using 4K pages, avoiding this CPU bug. In addition, it should also be possible to avoid this problem by not using AGP on affected systems.

Needless to say, this is a problem that affects many Linux gamers. The update also states that Alan Cox will be adding detection code in the kernel to avoid this issue altogether.

13 Responses to “WARNING – AMD CPU Bug”

  1. Anonymous Says:

    Does this lilo option change anything with my speed ?? Is it slower ??

    Peter

  2. Anonymous Says:

    …this may explain Mandrake’s flaky reputation on Athlons. Unlike most distros, they build everything optimized for the Pentium — including the kernel.

  3. Anonymous Says:

    So far, I’ve noticed that when the map switches in multiplayer UT, I get a crash to the desktop. I once got a complete system freeze when starting UT.

    Looks like I’ll have to give the workaround a try.

  4. friedmud Says:

    You have recompiled your kernel to be optimized for an Athlon? Becuase I have never had any problems on my 1.2Ghz with a Geforce3 – but I have recompiled most everything on my machine including my kernel, so I wonder if that has something to do with it.

    Anyone got an answer?

    Derek

  5. Maquis196 Says:

    I might have missed something somewhere,but ive looked around the Internet and I haven’t found a direct answer to;
    1]This bug,is it because of a problem with the Athlon that the 2.4.x Kernel has stumbled upon or is it a bug in 2.4.x kernel?
    and 2]Does it effect AGP in general or its it specific to NVAGP or AGPGart?

    Sorry for my nievite – But I like direct answers! Thanx to anyone who anwsers!

    Maquis196

  6. phneutre Says:

    To Alan Cox and Andrea Arcangeli, this bug is not what we think.

    ” That problem shouldnt be hitting Linux x86. I don’t know about the Nvidia module but the base kernel shouldnt hit an invlpg on 4Mb pages”
    http://www.uwsg.indiana.edu/hypermail/linux/kernel/0201.2/1352.html

    and:
    “furthmore it cannot even trigger if you invlpg with an address page aligned (4mbyte aligned in this case) like we would always do in linux anyways, we never use invlpg on misaligned addresses, no matter if the page is a 4M or a 4k page. And I guess with PAE enabled it cannot
    even trigger in first place (it speaks only about 4M pages, pae only provides 2M pages instead).

    I think this is a very very minor issue, I doubt anybody ever triggered it in real life with linux.”
    http://www.uwsg.indiana.edu/hypermail/linux/kernel/0201.2/1314.html

  7. Anonymous Says:

    I found this link while browsing, anyone who says Windows users aren’t complete morons just refer them to this link.
    http://slashdotsucks.com/?op=displaystory;sid=2002/1/21/102911/151

  8. Anonymous Says:

    I have been experiencing weard lockups with my Athlond 1,2G during 3D gaming after I updated to RH72. Only disabling AGP has worked for me at this time. Dunno if this gonna fix the problem but im definately gonna try.

    btw. Anyone know what default settings are in different distros?

  9. Anonymous Says:

    Further discussion on the linux-kernel mailing list suggests that the bug, if there is one, is more complicated than merely a paging issue — it may also be erroneously called an Athlon CPU bug, since it hinges on behviors of the AGP controller and such other strangeness. Check a linux-kernel archive for further discussion.

  10. Anonymous Says:

    Many thanks, yes I have received my full order with cheap accutane and hoodia . I have used other internet suppliers but you are the best of the best ! Thank you again for a brilliant product & service, buy hoodia and buy accutane .
    accutane cheap accutane buy accutane buy accutane online accutane cheap to buy where can i buy accutane
    - Kindest regards, Rod

  11. Anonymous Says:

    Dear Folk!
    How you have met Christmas?
    You have brought a smile to my face all year long. … I never would have met such a fun, interesting group of people.
    Mark Oem

  12. Anonymous Says:

    Dear Folk!
    How you have met Christmas?
    You have brought a smile to my face all year long. … I never would have met such a fun, interesting group of people.
    Mark Oem

  13. Anonymous Says:

    Dear Folk!
    How you have met Christmas?
    You have brought a smile to my face all year long. … I never would have met such a fun, interesting group of people.
    Mark Oem

Leave a Reply

You must be logged in to post a comment.