Spectre & Meltdown Defined January 2018

Written by Michael Larabel in Phoronix on 1 February 2018 at 11:30 AM EST. 9 Comments
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A majority of last month was spent looking at and testing/benchmarking the Linux code to mitigate the much talked about Spectre and Meltdown CPU vulnerabilities.

But even with all the extra testing work in January, your's truly still managed to write 41 featured articles/reviews and 313 original news articles on Phoronix, continuing with the trend of new content on Phoronix each and every day and averaging around 10 pieces of original content per day.


Below is a look at the most popular content on Phoronix for January 2018 in case you missed out on any of the exciting events, discussions, or Linux hardware reviews. If you appreciate all of the original reporting and often times exclusive benchmarks and other content, consider showing your support by joining Phoronix Premium, making a PayPal tip, or at the very least please not viewing this website with any ad-blocker. It's only through your support that Phoronix can continue now in its 14th year. While January was quite busy, even more exciting content on Phoronix will be coming up this month.

With that said here was the most-viewed featured articles for January:

Initial Benchmarks Of The Performance Impact Resulting From Linux's x86 Security Changes
Over the past day you've likely heard lots of hysteria about a yet-to-be-fully-disclosed vulnerability that appears to affect at least several generations of Intel CPUs and affects not only Linux but also Windows and macOS. The Intel CPU issue comes down to leaking information about the kernel memory to user-space, but the full scope isn't public yet until the bug's embargo, but it's expected to be a doozy in the data center / cloud deployments. Due to the amount of interest in this issue, here are benchmarks of a patched kernel showing the performance impact of the page table isolation patches.

Further Analyzing The Intel CPU "x86 PTI Issue" On More Systems
2018 has been off to a busy start with all the testing around the Linux x86 PTI (Page Table Isolation) patches for this "Intel CPU bug" that potentially dates back to the Pentium days but has yet to be fully disclosed. Here is the latest.

Linux KPTI Tests Using Linux 4.14 vs. 4.9 vs. 4.4
Yet another one of the avenues we have been exploring with our Linux Page Table Isolation (KPTI) testing has been looking at any impact of this security feature in the wake of the Meltdown vulnerability when testing with an older Linux Long Term Support (LTS) release. In particular, when using a kernel prior to the PCID (Process Context Identifier) support in the Linux kernel that is used to lessen the impact of KPTI.

VM Performance Showing Mixed Impact With Linux 4.15 KPTI Patches
Continuing on with our Linux Kernel Page Table Isolation (KPTI) performance testing are some benchmark results when running tests within a virtual machine on Xeon class hardware.

Benchmarking Linux With The Retpoline Patches For Spectre
While the Kernel Page Table Isolation (KPTI) patches were quick to land in the mainline Linux kernel for addressing the Meltdown CPU vulnerability, the "Retpoline" patches are still being worked on as the leading approach on the Linux side for dealing with the Spectre CPU vulnerability. The Retpoline patches are said to have little impact on performance, but here are our benchmarks of these kernel patches for seeing how they affect a variety of AMD and Intel systems.

The Fastest Linux Distribution For Ryzen: A 10-Way Linux OS Comparison On Ryzen 7 & Threadripper
While we frequently do Linux OS/distribution performance comparisons on the latest Intel desktop and server hardware, some requests came in recently about looking closer at the fastest Linux distribution(s) when running on AMD's Ryzen desktop processors. Here are benchmarks of ten popular Linux distributions tested out-of-the-box on Ryzen 7 1800X and Threadripper 1950X systems.

KPTI + Retpoline Linux Benchmarking On Old Laptops
Over the past week and a half of running many benchmarks looking at the performance impact of the Linux KPTI and Retpoline patches for Spectre and Meltdown mitigation, one of the most common test requests is some thorough benchmarks on older systems. Why that's important is with older (pre-Westmere) CPUs there isn't PCID (Process Context Identifier) support that's used by KPTI, which helps offset some of the performance loss. So for some test results to share today are two old ThinkPads from the Clarksfield and Penryn days compared to a newer Broadwell ThinkPad in looking at the performance difference.

Intel Graphics On Ubuntu: GNOME vs. KDE vs. Xfce vs. Unity vs. LXDE
For those wondering how the Intel (U)HD Graphics compare for games and other graphical benchmarks between desktop environments in 2018, here are some fresh benchmarks using GNOME Shell on X.Org/Wayland, KDE Plasma 5, Xfce, Unity 7, and LXDE.

Linux Gaming For Older/Lower-End Graphics Cards In 2018
A request came in this week to look at how low-end and older graphics cards are performing with current generation Linux games on OpenGL and Vulkan. With ten older/lower-end NVIDIA GeForce and AMD Radeon graphics cards, here is a look at their performance with a variety of native Linux games atop Ubuntu using the latest Radeon and NVIDIA drivers.

Tweaking Ubuntu 17.10 To Try To Run Like Clear Linux
Even with the overhead of having both KPTI and Retpoline kernel support in place, our recent Linux distribution benchmarks have shown Intel's Clear Linux generally outperforming the more popular distributions. But if applying some basic performance tweaks, can Ubuntu 17.10 perform like Clear Linux? Here are some benchmarks looking at a few factors.

And the most popular news:

Dell Rolls Out New XPS 13 Laptop For 2018
Just ahead of the Consumer Electronics Show (CES) in Las Vegas, Dell has unveiled a new XPS 13 high-end laptop.

Intel Rolls Out Their New CPUs With Radeon Vega M Graphics
Kicking off CES 2018, Intel launched their new CPUs featuring integrated Radeon Vega M Graphics.

AMD Cuts Ryzen Prices, Confirms New Hardware, New Ryzen CPUs With Vega
While Intel announced their new CPUs with Radeon Vega M graphics, AMD had a host of announcements on their own for getting CES 2018 started with some excitement.

Linux Gaming Performance Doesn't Appear Affected By The x86 PTI Work
With the recently published Initial Benchmarks Of The Performance Impact Resulting From Linux's x86 Security Changes, one of the common questions that came up is whether gaming performance is adversely affected by the x86 Page Table Isolation changes recently merged to the Linux kernel.

For Now At Least AMD CPUs Are Also Reported As "Insecure"
Right now with the big mysterious security vulnerability causing the rush of the x86 Page Table Isolation work that landed in the Linux kernel days ago, it's believed to be a problem only affecting Intel CPUs. But at least for now the mainline kernel is still treating AMD CPUs as "insecure" and is too taking a performance hit.

Linux Will End Up Disabling x86 PTI For AMD Processors - Update: Now Disabled
While at the moment with the mainline Linux kernel Git tree AMD CPUs enable x86 PTI and are treated as "insecure" CPUs, the AMD patch for not setting X86_BUG_CPU_INSECURE will end up being honored.

systemd Breached One Million Lines Of Code In 2017
Systemd had a busy 2017 and its code-base is now up to over one million lines.

Some Of The Features Coming To The Linux 4.16 Kernel
Linux 4.15 will hopefully be released later today and that will kick off the start of the Linux 4.16 kernel merge window. Here's some of what is coming to this next kernel cycle.

AMD PSP Affected By Vulnerability
While all eyes have been on Intel this week with the Spectre and Meltdown vulnerabilities, a disclosure was publicly made this week surrounding AMD's PSP Secure Processor in an unrelated security bulletin.

Google Makes Disclosure About The CPU Vulnerability Affecting Intel / AMD / ARM
We're finally getting actual technical details on the CPU vulnerability leading to the recent race around (K)PTI that when corrected may lead to slower performance in certain situations. Google has revealed they uncovered the issue last year and have now provided some technical bits.
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About The Author
Michael Larabel

Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via MichaelLarabel.com.

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