[Beowulf] [upgrade strategy] Intel CPU design bug & security flaw - kernel fix imposes performance penalty

[Richard Walsh]

All, 

Mmm ... maybe I am missing something, but for an HPC cluster-specific solution ... how about skipping the fixes, and simply requiring all compute node jobs to run in exclusive mode and then zero-ing out user memory between jobs ... ??

Individual job performance would be preserved, while there would be “only” a system throughput performance degradation.  Is it clear that this is measurably worse ... ??

Richard Walsh
Thrashing River Computing 

Sent from my iPhone

> On Jan 7, 2018, at 3:29 PM, Christopher Samuel <chris at csamuel.org> wrote:
> 
>> On 07/01/18 23:22, Jörg Saßmannshausen wrote:
>> 
>> the first court cases against Intel have been filed:
> 
> These would have to be Meldown related then, given that Spectre is so
> widely applicable.
> 
> Greg K-H has a useful post up about the state of play with the various
> Linux kernel patches for mainline and stable kernels here:
> 
> http://kroah.com/log/blog/2018/01/06/meltdown-status/
> 
> He also mentioned about the Meltdown patches for ARM64:
> 
> # Right now the ARM64 set of patches for the Meltdown issue are not
> # merged into Linus’s tree. They are staged and ready to be merged into
> # 4.16-rc1 once 4.15 is released in a few weeks. Because these patches
> # are not in a released kernel from Linus yet, I can not backport them
> # into the stable kernel releases (hey, we have rules for a reason...)
> #
> # Due to them not being in a released kernel, if you rely on ARM64 for
> # your systems (i.e. Android), I point you at the Android Common Kernel
> # tree All of the ARM64 fixes have been merged into the 3.18, 4.4, and
> # 4.9 branches as of this point in time.
> 
> All the best,
> Chris
> -- 
> Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC
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