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Energy-aware scheduling — running a system's workload in a way that minimizes the amount of energy consumed — has been a topic of active discussion and development for some time; LWN first covered the issue at the beginning of 2012. Many approaches have been tried during the intervening years, but little in the way of generalized energy-aware scheduling work has made it into the mainline. Recently, a new patch set was posted by Dietmar Eggemann that only tries to address one aspect of the problem; perhaps the problem domain has now been simplified enough that this support can finally be merged.
Here's the second part of Daniel Stone's series on recent improvements in low-level graphics support. "The end result of all this work is that we have been able to eliminate the magic side channels which used to proliferate, and lay the groundwork for properly communicating this information across multiple devices as well. Devices supporting ARM's AFBC compression format are just beginning to hit the market, which share a single compression format between video decoder, GPU, and display controller. We are also beginning to see GPUs from different vendors share tiling formats, in order to squeeze the most performance possible from hybrid GPU systems."
The LWN.net Weekly Edition for March 22, 2018 is available.
Inside this week's LWN.net Weekly Edition
Security updates have been issued by Debian (adminer, isc-dhcp, kamailio, libvorbisidec, plexus-utils2, and simplesamlphp), Fedora (exim and glibc-arm-linux-gnu), Mageia (sqlite3), openSUSE (Chromium, kernel, and qemu), SUSE (memcached), and Ubuntu (sharutils).
While updating kernels frequently is generally considered a security best practice, there are many installations that are unable to do so for a variety of reasons. That means running with some number of known vulnerabilities (along with an unknown number of unknown vulnerabilities, of course), so some way to detect and stop exploits for those flaws may be desired. That is exactly what the Linux Kernel Runtime Guard (LKRG) is meant to do.
It is an increasingly poorly kept secret that, underneath the hood of the components that most of us view as "hardware", there is a great deal of proprietary software. This code, written by anonymous developers, rarely sees the light of day; as a result, it tends to have all of the pathologies associated with software that nobody can either review or fix. The 2018 Embedded Linux Conference saw an announcement for a new project that, with luck, will change that situation, at least for one variety of hardware: audio devices.
Version 4.0 of the Krita drawing tool has been released; see this article for a summary of the new features in this release. "Krita 4.0 will use SVG on vector layers by default, instead of the prior reliance on ODG. SVG is the most widely used open format for vector graphics out there. Used by 'pure' vector design applications, SVG on Krita currently supports gradients and transparencies, with more effects coming soon."
Developers and maintainers of free-software projects are drawn from the same pool of people, and maintainers in one project are often developers in another, but there is still a certain amount of friction between the two groups. Maintainers depend on developers to contribute changes, but the two groups have a different set of incentives when it comes to reviewing and accepting those changes. Two talks at the 2018 Embedded Linux Conference shed some light on this relationship and how it can be made to work more smoothly.
Security updates have been issued by Arch Linux (lib32-libvorbis), Debian (exempi and polarssl), Gentoo (collectd and webkit-gtk), openSUSE (postgresql96), SUSE (qemu), and Ubuntu (libvorbis).
In my previous article, I gave an introduction to the open architecture of RISC-V. This article looks at how I and a small team of Fedora users ported a large part of the Fedora package set to RISC-V. It was a daunting task, especially when there is no real hardware or existing infrastructure, but we were able to get there in a part-time effort over a year and a half or so.
Subscribers can read on for a look at getting Fedora onto RISC-V by guest author Richard W.M. Jones.
"Syzbot" is an automated system that runs the syzkaller fuzzer on the kernel and reports the resulting crashes. Dmitry Vyukov has announced the availability of a web site displaying the outstanding reports. "The dashboard shows info about active bugs reported by syzbot. There are ~130 active bugs and I think ~2/3 of them are actionable (still happen and have a reproducer or are simple enough to debug)."
Some years ago, prominent community leaders doubted that even short-term stable maintenance of kernel releases was feasible. More recently, selecting an occasional kernel for a two-year maintenance cycle has become routine, and some kernels, such as 3.2 under the care of Ben Hutchings, have received constant maintenance for as much as six years. But even that sort of extended maintenance is not enough for some use cases, as Yoshitake Kobayashi explained in his Embedded Linux Conference talk. To meet those needs, the Civil Infrastructure Platform (CIP) project is setting out to maintain releases for a minimum of 20 years.
Version 5.4 of the RawTherapee image-processing tool is out. New features include a new histogram-matching tool, a new HDR tone-mapping tool, a number of user-interface and performance improvements, and quite a bit more.
Alex Shi's posting of a patch series backporting a set of Meltdown fixes for the arm64 architecture to the 4.9 kernel might seem like a normal exercise in making important security fixes available on older kernels. But this case raised a couple of interesting questions about why this backport should be accepted into the long-term-support kernels — and a couple of equally interesting answers, one of which was rather better received than the other.
The LWN.net Weekly Edition for March 15, 2018 is available.
Inside this week's LWN.net Weekly Edition
Security updates have been issued by CentOS (firefox), Debian (plexus-utils), Fedora (calibre, cryptopp, curl, dolphin-emu, firefox, golang, jhead, kernel, libcdio, libgit2, libvorbis, ming, net-snmp, patch, samba, xen, and zsh), Red Hat (collectd and rh-mariadb101-mariadb and rh-mariadb101-galera), and Ubuntu (paramiko and tiff).
As is often the case, the python-ideas mailing list hosted a discussion about a Python Enhancement Proposal (PEP) recently. In some sense, this particular PEP was created to try to gather together the pros and cons of a feature idea that regularly crops up: statement-local bindings for variable names. But the discussion of the PEP went in enough different directions that it led to calls for an entirely different type of medium in which to have those kinds of discussions.
Daniel Stone begins a series on how the Linux graphic stack has improved in recent times. "This has made mainline Linux much more attractive: the exact same generic codebases of GNOME and Weston that I'm using to write this blog post on an Intel laptop run equally well on AMD workstations, low-power NXP boards destined for in-flight entertainment, and high-end Renesas SoCs which might well be in your car. Now that the drivers are easy to write, and applications are portable, we've seen over ten new DRM drivers merged to the upstream kernel since atomic modesetting was merged."
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