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LWN.net is a comprehensive source of news and opinions from and about the Linux community. This is the main LWN.net feed, listing all articles which are posted to the site front page.
Updated: 1 hour 11 min ago

Some weekend stable kernel updates

Saturday 15th of June 2019 04:52:02 PM
There's yet another set of stable kernel updates out there: 5.1.10, 4.19.51, and 4.14.126. Each contains another set of important fixes.

[$] Dueling memory-management performance regressions

Friday 14th of June 2019 04:04:05 PM
The 2019 Linux Storage, Filesystem, and Memory-Management Summit included a detailed discussion about a memory-management fix that addressed one performance regression while causing another. That fix, which was promptly reverted, is still believed by most memory-management developers to implement the correct behavior, so a patch posted by Andrea Arcangeli in early May has relatively broad support. That patch remains unapplied as of this writing, but the discussion surrounding it has continued at a slow pace over the last month. Memory-management subsystem maintainer Andrew Morton is faced with a choice: which performance regression is more important?

Security updates for Friday

Friday 14th of June 2019 02:15:54 PM
Security updates have been issued by Arch Linux (gvim, lib32-openssl, openssl, and vim), Debian (dbus), Fedora (dovecot, evince, js-jquery-jstree, libxslt, php-phpmyadmin-sql-parser, and phpMyAdmin), openSUSE (neovim and rubygem-rack), Oracle (docker-engine and python), Scientific Linux (python), Slackware (mozilla), and SUSE (containerd, docker, docker-runc, go, go1.11, go1.12, golang-github-docker-libnetwork, elfutils, libvirt, and python-requests).

[$] Short waits with umwait

Thursday 13th of June 2019 05:04:51 PM
If a user-space process needs to wait for some event to happen, there is a whole range of mechanisms provided by the kernel to make that easy. But calling into the kernel tends not to work well for the shortest of waits — those measured in small numbers of microseconds. For delays of this magnitude, developers often resort to busy loops, which have a much smaller potential for turning a small delay into a larger one. Needless to say, busy waiting has its own disadvantages, so Intel has come up with a set of instructions to support short delays. A patch set from Fenghua Yu to support these instructions is currently working its way through the review process.

Security updates for Thursday

Thursday 13th of June 2019 01:02:57 PM
Security updates have been issued by Fedora (firefox, kernel, kernel-headers, libreswan, python-urllib3, and vim), Red Hat (python), SUSE (sssd), and Ubuntu (dbus).

[$] LWN.net Weekly Edition for June 13, 2019

Thursday 13th of June 2019 12:51:50 AM
The LWN.net Weekly Edition for June 13, 2019 is available.

[$] Paying (some) Debian developers

Wednesday 12th of June 2019 09:56:34 PM
In an offshoot of the Debian discussion we looked at last week, the Debian project has been discussing the idea of paying developers to work on the distribution. There is some history behind the idea, going back to the controversial Dunc-Tank initiative in 2006, but some think attitudes toward funding developers may have changed—or that a new approach might be better accepted. While it is playing out with regard to Debian right now, it is a topic that other projects have struggled with along the way—and surely will again.

Security updates for Wednesday

Wednesday 12th of June 2019 03:17:11 PM
Security updates have been issued by Debian (libgd2, mediawiki, otrs2, vlc, and zookeeper), Fedora (containernetworking-plugins, kernel, kernel-headers, nodejs-tough-cookie, podman, python-django, and python-urllib3), openSUSE (virtualbox), SUSE (gnome-shell, libcroco, and php7), and Ubuntu (dbus, Neovim, and vim).

[$] Python and "dead" batteries

Wednesday 12th of June 2019 12:44:54 PM
Python is, famously, a "batteries included" language; it comes with a rich standard library right out of the box, which makes for a highly useful starting point for everyone. But that does have some downsides as well. The standard library modules are largely maintained by the CPython core developers, which adds to their duties; the modules themselves are subject to the CPython release schedule, which may be suboptimal. For those reasons and others, there have been thoughts about retiring some of the older modules; it is a topic that has come up several times over the last year or so.

Introducing Matrix 1.0 and the Matrix.org Foundation

Tuesday 11th of June 2019 08:31:47 PM
The Matrix team has announced the first stable release of the Matrix protocol and specification across all APIs. The Synapse 1.0 reference implementation, which implements the full Matrix 1.0 API surface, has also been released. "Now, before you get too excited, it’s critical to understand that Matrix 1.0 is all about providing a stable, self-consistent, self-contained and secure version of the standard which anyone should be able to use to independently implement production-grade Matrix clients, servers, bots and bridges etc. It does not mean that all planned or possible features in Matrix are now specified and implemented, but that the most important core of the protocol is a well-defined stable platform for everyone to build on. On the Synapse side, our focus has been exclusively on ensuring that Synapse correctly implements Matrix 1.0, to provide a stable and secure basis for participating in Matrix without risk of room corruption or other nastinesses." The announcement also covers the launch of the Matrix.org Foundation.

[$] Generalized events notification and security policies

Tuesday 11th of June 2019 03:29:30 PM
Interfaces for the reporting of events to user space from the kernel have been a recurring topic on the kernel mailing lists for almost as long as the kernel has existed; LWN covered one 15 years ago, for example. Numerous special-purpose event-reporting APIs exist, but there are none that are designed to be a single place to obtain any type of event. David Howells is the latest to attempt to change that situation with a new notification interface that, naturally, uses a ring buffer to transfer events to user space without the need to make system calls. The API itself (which hasn't changed greatly since it was posted in 2018) is not hugely controversial, but the associated security model has inspired a few heated discussions.

Five new stable kernels

Tuesday 11th of June 2019 02:50:19 PM
Stable kernels 5.1.9, 4.19.50, 4.14.125, 4.9.181, and 4.4.181 have been released. They all contain important fixes and users should upgrade.

Security updates for Tuesday

Tuesday 11th of June 2019 02:36:28 PM
Security updates have been issued by CentOS (bind and thunderbird), Mageia (firefox, ghostscript, graphicsmagick, imagemagick, postgresql, and thunderbird), Oracle (kernel), Red Hat (Advanced Virtualization and rh-haproxy18-haproxy), SUSE (bind, gstreamer-0_10-plugins-base, thunderbird, and vim), and Ubuntu (elfutils, glib2.0, and libsndfile).

[$] BPF for security—and chaos—in Kubernetes

Monday 10th of June 2019 04:41:45 PM
BPF is probably familiar to many LWN readers, though it's likely not yet quite as well known in the Kubernetes community — but that could soon change. At KubeCon + CloudNativeCon Europe 2019 there were multiple sessions with BPF in the title where developers talked about how BPF can be used to help with Kubernetes security, monitoring, and even chaos engineering testing. We will look at two of those talks that were led by engineers closely aligned with the open-source Cilium project, which is all about bringing BPF to Kubernetes container environments. Thomas Graf, who contributes to BPF development in the Linux kernel, led a session on transparent chaos testing with Envoy, Cilium, and BPF, while his counterpart Dan Wendlandt, who is well known in the OpenStack community for helping to start the Neutron networking project, spoke about using the kernel's BPF capabilities to add visibility and security in a Kubernetes-aware manner.

Security updates for Monday

Monday 10th of June 2019 02:12:25 PM
Security updates have been issued by Arch Linux (chromium and pam-u2f), Debian (cyrus-imapd), Fedora (curl, cyrus-imapd, kernel, kernel-headers, php, and vim), openSUSE (axis, bind, bubblewrap, evolution, firefox, gnome-shell, libpng16, and rmt-server), Oracle (edk2 and kernel), and SUSE (bind, cloud7, and libvirt).

Kernel prepatch 5.2-rc4

Monday 10th of June 2019 02:09:47 PM
The 5.2-rc4 kernel prepatch is out for testing. "We've had a fairly calm release so far, and on the whole that seems to hold. rc4 isn't smaller than rc3 was (it's a bit bigger), but rc3 was fairly small, so the size increase isn't all that worrisome. I do hope that we'll start actually shrinking now, though."

Stable kernel updates

Monday 10th of June 2019 12:45:06 PM
The 5.1.8, 4.19.49, and 4.14.124 stable kernel updates have been released; each contains another set of important fixes.

[$] Detecting and handling split locks

Friday 7th of June 2019 04:56:29 PM
The Intel architecture allows misaligned memory access in situations where other architectures (such as ARM or RISC-V) do not. One such situation is atomic operations on memory that is split across two cache lines. This feature is largely unknown, but its impact is even less so. It turns out that the performance and security impact can be significant, breaking realtime applications or allowing a rogue application to slow the system as a whole. Recently, Fenghua Yu has been working on detecting and fixing these issues in the split-lock patch set, which is currently on its eighth revision.

Security updates for Friday

Friday 7th of June 2019 01:11:18 PM
Security updates have been issued by Debian (evolution and qemu), Fedora (cyrus-imapd and hostapd), Gentoo (exim), openSUSE (exim), Red Hat (qpid-proton), SUSE (bind, libvirt, mariadb, mariadb-connector-c, python, and rubygem-rack), and Ubuntu (firefox, jinja2, and linux-lts-xenial, linux-aws).

[$] Renaming openSUSE

Thursday 6th of June 2019 03:52:14 PM
In mid-May, LWN reported on the discussions in the openSUSE project over whether a separation from SUSE would be a good move. It would appear that this issue has been resolved and that openSUSE will be setting up a foundation as its new home independent of the SUSE corporation. But now the community has been overtaken by a new, related discussion that demonstrates a characteristic of free-software projects: the hardest issues are usually related to naming.

More in Tux Machines

Today in Techrights

today's leftovers

  • Georges Basile Stavracas Neto: Calendar management dialog, archiving task lists, Every Detail Matters on Settings (Sprint 2)
    This was a long-time request, and something that I myself was missing when using To Do. Since it fits well with the product vision of the app, there was nothing preventing it from being implemented. Selecting this feature to be implemented during the week was a great choice – the task was self contained, had a clear end, and was just difficult just enough to be challenging but not more than that. However, I found a few issues with the implementation, and want to use the next round to polish the feature. Using the entire week to polish the feature might be too much, but it will give me some time to really make it great.
  • Open Source Answer To Dropbox And OneDrive: Meet Frank Karlitschek
    During the OpenSUSE Conference in Nurnberg (German), Nextcloud founder Frank Karlitschek appeared on “Let’s Talk’ to talk about the importance of fully open source file sync and storage solutions for enterprise customers. As one of the early contributors to desktop Linux he also talked about the reasons why desktop Linux has not succeeded.
  • Load-Bearing Internet People
    Some maintainers for critical software operate from a niche at a university or a government agency that supports their effort. There might be a few who are independently wealthy.
  • Robert Helmer: Vectiv and the Browser Monoculture
    So, so tired of the "hot take" that having a single browser engine implementation is good, and there is no value to having multiple implementations of a standard. I have a little story to tell about this. In the late 90s, I worked for a company called Vectiv. There isn't much info on the web (the name has been used by other companies in the meantime), this old press release is one of the few I can find. Vectiv was a web-based service for commercial real estate departments doing site selection. This was pretty revolutionary at the time, as the state-of-the-art for most of these was to buy a bunch of paper maps and put them up on the walls, using push-pins to keep track of current and possible store locations. The story of Vectiv is interesting on its own, but the relevant bit to this story is that it was written for and tested exclusively in IE 5.5 for Windows, as was the style at the time. The once-dominant Netscape browser had plummeted to negligible market share, and was struggling to rewrite Netscape 6 to be based on the open-source Mozilla Suite.

OSS Leftovers

  • Letter of Recommendation: Bug Fixes
    I wouldn’t expect a nonprogrammer to understand the above, but you can intuit some of what’s going on: that we don’t need ImageMagick to scale images anymore, because the text editor can scale images on its own; that it’s bad form to spell-check hex values, which specify colors; that the bell is doing something peculiar if someone holds down the alt key; and so forth. But there’s also something larger, more gladdening, about reading bug fixes. My text editor, Emacs, is a free software project with a history going back more than 40 years; the codebase itself starts in the 1980s, and as I write this there are 136,586 different commits that get you from then to now. More than 600 contributors have worked on it. I find those numbers magical: A huge, complex system that edits all kinds of files started from nothing and then, with nearly 140,000 documented human actions, arrived at its current state. It has leaders but no owner, and it will move along the path in which people take it. It’s the ship of Theseus in code form. I’ve probably used Emacs every day for more than two decades. It has changed me, too. It will outlive me. Open source is a movement, and even the charitably inclined would call it an extreme brofest. So there’s drama. People fight it out in comments, over everything from semicolons to codes of conduct. But in the end, the software works or it doesn’t. Politics, our personal health, our careers or lives in general — these do not provide a narrative of unalloyed progress. But software, dammit, can and does. It’s a pleasure to watch the code change and improve, and it’s also fascinating to see big companies, paid programmers and volunteers learning to work together (the Defense Department is way into open source) to make those changes and improvements. I read the change logs, and I think: Humans can do things.
  • The Top 17 Free and Open Source Network Monitoring Tools
    Choosing the right network monitoring solution for your enterprise is not easy.
  • Hedge-fund managers are overwhelmed by data, and they're turning to an unlikely source: random people on the internet
    Alternative data streams of satellite images and cellphone-location data are where managers are now digging for alpha, as new datasets are created every day. And hedge funds have been spending serious cash searching for those who can take all this information and quickly find the important pieces. Now, as margins shrink and returns are under the microscope, hedge funds are beginning to consider a cheaper, potentially more efficient way to crunch all this data: open-source platforms, where hundreds of thousands of people ranging from finance professionals to students, scientists, and developers worldwide scour datasets — and don't get paid unless they find something that a fund finds useful.
  • TD Ameritrade Is Taking Its First Steps Towards Major Open Source Contributions
    STUMPY is a python library to identify the patterns and anomalies in time series data. STUMPY has benefited from open source as a means to shorten development roadmaps since the early 2000s and it represents a new opportunity for TD Ameritrade to give back to the developer community.
  • The Future of Open Source Big Data Platforms
    Three well-funded startups – Cloudera Inc., Hortonworks Inc., and MapR Technologies Inc. — emerged a decade ago to commercialize products and services in the open-source ecosystem around Hadoop, a popular software framework for processing huge amounts of data. The hype peaked in early 2014 when Cloudera raised a massive $900 million funding round, valuing it at $4.1 billion.
  • No Easy Way Forward For Commercial Open Source Software Vendors
    While still a student in 1995, Kimball developed the first version of GNU Image Manipulation Program (GIMP) as a class project, along with Peter Mattis. Later on as a Google engineer, he worked on a new version of the Google File System, and the Google Servlet Engine. In 2012, Kimball, Mattis, and Brian McGinnis launched the company Viewfinder, later selling it to Square.
  • 6 Reasons Why Developers Should Contribute More To Open Source
    Even by fixing minor things like a bug in a library or writing a piece of documentation can also help the developers to write readable or maintainable code. They can independently suggest to the community and generally tend to stick by the rules of writing a code that is easy to understand. The fact that the code will be exposed to everyone naturally makes them write focus on making it readable.
  • WIDE Project, KDDI develop router with open-source software, 3.2T-packet transmission
    The WIDE Project has adopted a router developed by Japanese operator KDDI. The router runs open-source software, and will be used with the networks operated and managed by the WIDE Project. The router will use open-source software with up to 3.2T-packet transmission. For this project, KDDI plans to start tests this month to verify the practical utility and interoperability of these routers when put to use in the actual service environment. The WIDE Project will be in charge of network administration and definition of requirements for router implementation.
  • Lack of progress in open source adoption hindering global custody’s digitisation
    Custody industry is lagging behind the rest of the financial services sector for open source projects, according to industry experts.
  • TNF: Industry should be focusing on open source development
    According to O'Shea, open source and the community are helping firms to find and attract experienced technology talent “uber engineers”.
  • Google Open Sources TensorNetwork , A Library For Faster ML And Physics Tasks
    “Every evolving intelligence will eventually encounter certain very special ideas – e.g., about arithmetic, causal reasoning and economics–because these particular ideas are very much simpler than other ideas with similar uses,” said the AI maverick Marvin Minsky four decades ago. Mathematics as a tool to interpret nature’s most confounding problems from molecular biology to quantum mechanics has so far been successful. Though there aren’t any complete answers to these problems, the techniques within domain help throw some light on the obscure corners of reality.
  • Open source to become a ‘best practice’
    There are many magic rings in this world… and none of them should be used lightly. This is true. It is also true that organisations in every vertical are now having to work hard and find automation streams that they can digitise (on the road to *yawn* digital transformation, obviously) and start to apply AI and machine learning to. Another key truth lies in the amount of codified best practices that organisations now have the opportunity to lay down. One we can denote a particular set of workflows in a particular department (or team, or group, or any other collective) to be deemed to be as efficient as possible, then we can lay that process down as a best practice.
  • 10 Open-Source and Free CAD Software You Can Download Right Now
    Many CAD software products exist today for anyone interested in 2D or 3D designing. From browser tools to open-source programs, the market is full of free options available for hobbyists or small companies just starting out.

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