(forw) Re: [DNG] [WARNING] Intel Skylake/Kaby Lake processors: broken hyper-threading
Rick Moen <rick-IyCrq+X4Fdq2oZ/[email protected]>
| Newsgroups | gmane.org.user-groups.linux.svlug |
|---|---|
| Organization | If you lived here, you'd be $HOME already. |
| Message-ID | <[email protected]> |
----- Forwarded message from Andrew McGlashan <andrew.mcglashan-eCNwZfdMfp8leAitJ8REmSkBLnlaf3ui@public.gmane.org> ----- Date: Mon, 26 Jun 2017 17:55:31 +1000 From: Andrew McGlashan <andrew.mcglashan-eCNwZfdMfp8leAitJ8REmSkBLnlaf3ui@public.gmane.org> To: Devuan DNG <[email protected]> Subject: Re: [DNG] [WARNING] Intel Skylake/Kaby Lake processors: broken hyper-threading -- update from original posteer -- Minor update on the issue: The check command provided in the advisory to test for hyper-threading doesn't work: it will always report hyper-theading as enabled. A better command is provided below. Note: this also means the perl script will give some false-positives. I apologise for the inconvenience. On Sun, 25 Jun 2017, Henrique de Moraes Holschuh wrote: > Once you know your processor model name, you can check the two lists > below: > > * List of Intel processors code-named "Skylake": > http://ark.intel.com/products/codename/37572/Skylake > > * List of Intel processors code-named "Kaby Lake": > http://ark.intel.com/products/codename/82879/Kaby-Lake > > Some of the processors in these two lists are not affected because they > lack hyper-threading support. Run the command below in a command line > shell (e.g. xterm), and it will output a message if hyper-threading is > supported/enabled: > > grep -q '^flags.*[[:space:]]ht[[:space:]]' /proc/cpuinfo && \ > echo "Hyper-threading is supported" The above test (using "grep") does not work, and will always report that hyper-threading is enabled. Please use the "lscpu" utility from the util-linux package in a command line shell (e.g. xterm): lscpu If the lscpu output reports: "Thread(s) per core: 2", that means hyper-threading is enabled and supported. If the lscpu output reports: "Thread(s) per core: 1", that means hyper-threading either disabled or not supported. In this case, the specific defect mentioned in the advisory will not trigger. -- Henrique Holschuh _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng ----- End forwarded message -----