[kwlug-disc] Meltown fix for Linux kernel

[Bob Jonkman]

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Ubuntu is having its problems lately.  In December they had the BIOS
corruption bug on 17.10:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1734147

I'm in the process of switching all our home computers to Debian
Testing and the servers to Debian Stable. Previously had a mixture of
Ubuntu 16.04, 14.04, Mint with Mate, Debian Jessie, and who knows what
else.  But I don't think it'll help avoid these latest kernel bugs...

- --Bob

On 2018-01-11 03:24 PM, doug moen wrote:
> The Ubuntu bug is here: 
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1742323
> 
> The problem is that, after upgrading to kernel 4.4.0-108, some
> systems won't boot.
> 
> Most people with this problem report that upgrading to 4.4.0-109
> (which is now in the Ubuntu repositories) fixes the problem.
> 
> However, bug 1742323 is still open and being worked on (marked
> critical).
> 
> On 10 January 2018 at 18:04, Khalid Baheyeldin <kb at 2bits.com>
> wrote:
> 
>> And Ubuntu 16.04 users can't reboot the new kernel after applying
>> the fixes.
>> 
>> Not a big deal if it is a desktop. If it is a dedicated server in
>> a data center, then it is downtime + support headaches.
>> 
>> https://news.slashdot.org/story/18/01/10/1634215/ 
>> meltdown-and-spectre-patches-bricking-ubuntu-1604-computers
>> 
>> On Wed, Jan 10, 2018 at 9:24 AM, Khalid Baheyeldin <kb at 2bits.com>
>> wrote:
>> 
>>> Wow, the differences are significant ...
>>> 
>>> For a dedicated server, the fix for Meltdown is not really
>>> needed, since no one else is accessing RAM by exploiting the
>>> speculative execution.
>>> 
>>> So I am thinking of pinning the kernel to what it is on those
>>> machines.
>>> 
>>> But there are also headers, generic, ...etc.
>>> 
>>> Anyone tried that?
>>> 
>>> 
>>> 
>>> On Wed, Jan 10, 2018 at 8:31 AM, L.D. Paniak < 
>>> ldpaniak at fourpisolutions.com> wrote:
>>> 
>>>> Looks like you will see substantial performance impact for
>>>> I/O-heavy workloads (especially synthetic ones):
>>>> 
>>>> https://www.phoronix.com/scan.php?page=news_item&px=KPTI-Ret 
>>>> poline-Combined-Ubuntu
>>>> 
>>>> The Apache server numbers are especially notable.
>>>> 
>>>> 
>>>> 
>>>> On 01/09/2018 07:18 PM, doug moen wrote:
>>>> 
>>>> According to what I read, the performance impact occurs if
>>>> you are hammering the kernel with a lot of system calls. Eg,
>>>> a server that is performing a lot of I/o.
>>>> 
>>>> On Tuesday, 9 January 2018, Khalid Baheyeldin <kb at 2bits.com>
>>>> wrote:
>>>> 
>>>>> I just received the email for the meltdown patch for Ubuntu
>>>>> Linux.
>>>>> 
>>>>> CVE-2017-5754
>>>>> 
>>>>> There are two concerns:
>>>>> 
>>>>> 1. Performance impact.
>>>>> 
>>>>> 2. This comment in the email:
>>>>> 
>>>>> "ATTENTION: Due to an unavoidable ABI change the kernel
>>>>> updates have been given a new version number, which
>>>>> requires you to recompile and reinstall all third party
>>>>> kernel modules you might have installed. Unless you
>>>>> manually uninstalled the standard kernel metapackages (e.g.
>>>>> linux-generic, linux-generic-lts-RELEASE, linux-virtual, 
>>>>> linux-powerpc), a standard system upgrade will
>>>>> automatically perform this as well."
>>>>> 
>>>>> Anyone updated to this fix yet? Any noticeable negative
>>>>> impact on performance?
>>>>> 
>>>>> -- Khalid M. Baheyeldin 2bits.com, Inc. Fast Reliable
>>>>> Drupal Drupal optimization, development, customization and
>>>>> consulting. Simplicity is prerequisite for reliability. --
>>>>> Edsger W.Dijkstra Simplicity is the ultimate
>>>>> sophistication. --   Leonardo da Vinci For every complex
>>>>> problem, there is an answer that is clear, simple, and
>>>>> wrong." -- H.L. Mencken
>>>>> 
>>>> 
>>>> 
>>>> _______________________________________________ kwlug-disc
>>>> mailing
>>>> listkwlug-disc at kwlug.orghttp://kwlug.org/mailman/listinfo/kwlug-disc_kwlug.org
>>>>
>>>>
>>>>
>>>>
>>>> 
_______________________________________________
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>>>> 
>>>> 
>>> 
>>> 
>>> -- Khalid M. Baheyeldin 2bits.com, Inc. Fast Reliable Drupal 
>>> Drupal optimization, development, customization and
>>> consulting. Simplicity is prerequisite for reliability. --
>>> Edsger W.Dijkstra Simplicity is the ultimate sophistication. --
>>> Leonardo da Vinci For every complex problem, there is an answer
>>> that is clear, simple, and wrong." -- H.L. Mencken
>>> 
>> 
>> 
>> 
>> -- Khalid M. Baheyeldin 2bits.com, Inc. Fast Reliable Drupal 
>> Drupal optimization, development, customization and consulting. 
>> Simplicity is prerequisite for reliability. --  Edsger
>> W.Dijkstra Simplicity is the ultimate sophistication. --
>> Leonardo da Vinci For every complex problem, there is an answer
>> that is clear, simple, and wrong." -- H.L. Mencken
>> 
>> _______________________________________________ kwlug-disc
>> mailing list kwlug-disc at kwlug.org 
>> http://kwlug.org/mailman/listinfo/kwlug-disc_kwlug.org
>> 
>> 
> 
> 
> 
> _______________________________________________ kwlug-disc mailing
> list kwlug-disc at kwlug.org 
> http://kwlug.org/mailman/listinfo/kwlug-disc_kwlug.org
> 

- -- 
Bob Jonkman <bjonkman at sobac.com>          Phone: +1-519-635-9413
SOBAC Microcomputer Services             http://sobac.com/sobac/
Software   ---   Office & Business Automation   ---   Consulting
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