There is the phenomenon on Linux where when double-buffered rendering and missing vblanks can lead to the GPU running at a lower frequency when instead the opposite should happen so it will try to not miss vblanks in the first place. In the past there's been talks of "boost" support in the GPU drivers or also workarounds from user-space like dynamic triple buffering, but sent out this week is a new proposal around DMA-Fence deadline awareness as another means of addressing this problem.

Google engineers and other parties are interested in being able to create swap spaces on Linux systems that would be reserved just for system suspend/hibernation purposes and not for generic swapping to disk.

Following last week's big kernel in the form of Linux 5.14-rc2, rc3 is now available and it's much saner this week with fewer changes and those scattered changes being on the smaller side.

The latest Linux kernel feature proposed by Microsoft that is now working its way to the mainline kernel is IMA-based target measurements for the Device Mapper (DM) subsystem for enhanced security.

One of the low-level exciting kernel advancements being worked on at the moment is the new "folios" struct for improving Linux memory management. Tests by those involved found that in some conditions Linux kernel builds for example could be up to 7% faster. Given the recent folios v14 patches being published, I took them for a spin on an AMD EPYC server to see the impact on overall performance.

Another weekly batch of drm-misc-next patches were submitted on Thursday for going into DRM-Next ahead of the Linux 5.15 merge window. This drm-misc-next material continues to represent core Direct Rendering Manager changes as well as alterations/additions to the smaller DRM drivers.

The latest BPF functionality set to appear with Linux 5.15 this autumn is timers support.

Amazon's DAMON is looking like it might be near for mainlining into the Linux kernel for this "Data Access Monitor". One of the follow-up patches that builds off DAMON that is also being pursued by Amazon engineers for proactive reclamation of memory pages.

Linus Torvalds just released Linux 5.14-rc2 as the latest weekly test candidate of the maturing Linux 5.14 kernel.

An early batch of "drm-misc-next" changes has been sent to DRM-Next for queuing to ultimately land with the Linux 5.15 kernel.

At the start of 2020 Amazon engineers sent out a "request for comments" around DAMON as a new kernel feature to monitor data accesses and can be used for purposes like analyzing over-committed memory use, debugging, and other optimizations. DAMON has now seen thirty-four revisions to the patches but it looks like it could finally be in a state for mainlining in the Linux kernel.

Matthew Wilcox of Oracle has sent out his 14th revision to the memory "folios" patch-set for this new struct that aims to improve Linux's memory management code and ultimately better performance.

Patches have been posted for wiring up Display Stream Compression (DSC) support for the Qualcomm MSM Direct Rendering Manager driver.

It's well known that the Linux desktop can be quite unbearable when under heavy memory pressure as has been showcased over the years and more attention these days turning to the likes of OOMD/systemd-oomd and other alternatives to better deal with Linux low/out-of-memory scenarios especially with today's desktop software and web browsers consuming increasing amounts of memory. Another effort coming to fruition for helping this scenario is the "le9" Linux kernel patches.

Being worked on for quite a while now by longtime kernel developer Matthew Wilcox of Oracle is memory folios to improve Linux's memory management and allow for greater efficiency. Benchmarks with memory folios have shown for example kernel builds can be up to 7% faster. It's looking like there is a desire to see at least some of this folios code land for Linux 5.15.

While there are the likes of OOMD / systemd-oomd gaining acceptance as a daemon for Linux systems to deal with killing off processes and other behavior under system memory (RAM) pressure, there still is an issue of the time it takes until the memory is reclaimed by those dying processes. Google engineers at the end of June proposed "process_reap" as a new system call to help in that memory recovery.

Following the two-week long merge window, the first release candidate to Linux 5.14 is now available with all the shiny new features to be found in this next kernel release.

The "memfd_secret" system call is being added to the Linux 5.14 kernel to provide the ability to create memory areas that are visible only in the context of the owning process and these "secret" memory regions are not mapped by other processes or the kernel page tables.

For over one year now since Advanced Matrix Extensions (AMX) was first disclosed as a future feature with Xeon "Sapphire Rapids", Intel engineers have been posting AMX patches for enabling the new support for changes needed from the kernel to code compiler stacks. The Linux kernel support for AMX hasn't yet landed but has now been revised its seventh time for public review.

The Linux 5.14 char/misc updates landed this week in the kernel. The "char/misc" area continues to serve as a growing catch-all portion of the code-base not jiving well elsewhere in other subsystems.

FUTEX2 continues to be worked on by Collabora as part of their work with Valve on enhancing Linux gaming support. With FUTEX2 the work is driven about enhancing the support for Windows games running on Linux with the likes of Steam Play.

Thomas Gleixner has announced the release of the real-time "RT" patches for the Linux 5.13, the first update since the patches were re-based early on back during the 5.12 release candidates.

The Linux 5.14 kernel so far is running smoothly in my early tests across a variety of systems but coming in this morning is a pull request having the potential to cause some fall-out on x86/x86_64 systems but hopefully will not.

The staging changes were submitted on Monday for the ongoing Linux 5.14 for this area of the kernel where immature / yet-to-be-cleaned-up code lives to prove itself before being ready to graduate to the proper mainline kernel area.

While RISC-V secures much of the spotlight these days when it comes to open-source processor instruction set architectures, OpenRISC is still moving along and soon should see more OpenRISC LiteX drivers upstreamed.

Greg Kroah-Hartman on mailed in the USB/Thunderbolt changes targeting the Linux 5.14 merge window.

The tracing subsystem within the Linux kernel is seeing some exciting improvements with Linux 5.14 to help with low-latency analysis and also measuring operating system noise.

The Linux kernel's tooling around the perf subsystem is the latest area seeing a lot of work for Intel's upcoming Alder Lake processors with a mix of high performance and low power processor cores.

Among the many new features that were sent in so far this week for the Linux 5.14 merge window was the long in-development work on "core scheduling" to reduce the Hyper Threading information leakage risks from side channels and help ensuring deterministic performance on such HT/SMT systems by controlling the resources that can run on a sibling thread. As a follow-up to that article from a few days ago, core scheduling will now be disabled by default.

The Linux 5.14 RAS (Reliability, Availability and Serviceability) and EDAC (Error Detection And Correction) changes have landed with several improvements this time around on the Intel side.