Yesterday I tweeted out the warning message about the HT bug of Skylake and Kaby Lake processors posted on debian.org.

https://lists.debian.org/debian-devel/2017/06/msg00308.html

My tweet got a LOT of retweets. A lot replied with concerns about their systems. I believe most Data Centers will not suffer from this bug as it is present on Skylake and Kaby Lake processors.

What is the Bug?

According to the warning: Unfixed Skylake and Kaby Lake processors could, in some

situations, dangerously misbehave when hyper-threading is enabled.

Disable hyper-threading immediately in BIOS/UEFI to work around the problem. Read this advisory for instructions about an Intel-provided fix.

https://www.intel.com/content/www/us/en/processors/xeon/xeon-e3-1200v5-spec-update.html

Unlikely Present in Your Data Center

The reason why I believe most systems in data centers are not hit by this bug is that it solely applies to E3 Xeons from the Skylake microarchitecture. E3 CPUs are designed to operate in a single socket system, they have no QuickPath Interconnect. Therefore unable to create a symmetric multiprocessing system.

The current E5 (dual-socket) system is based on the Broadwell microarchitecture. The Skylake microarchitecture is expected to appear within the next couple of months. According to the report, they will have the fix included when the product launched. If you are running a NUC in your lab, you might want to check to see whether your system might hit that bug

http://ark.intel.com/products/codename/82879/Kaby-Lake

http://ark.intel.com/products/codename/37572/Skylake

The link will forward you to a perl script that can help detect if your

system is affected or not. Many thanks to Uwe Kleine-König for

suggesting, and writing this script.

https://lists.debian.org/debian-devel/2017/06/msg00309.html

–