4 év 4 hónap óta
Part 1 of this series described the
copy-on-write (COW) mechanism used to avoid unnecessary copying of pages in
memory, then went into the details of a bug in that mechanism that
could result in the disclosure of sensitive data. A patch written by Linus
Torvalds and merged for the 5.8 kernel appeared to fix that problem without
unfortunate side effects elsewhere in the system. But COW is a complicated
beast and surprises are not uncommon; this particular story was nowhere
near as close to an end as had been thought.
corbet
4 év 4 hónap óta
The Free Software Foundation has
announced
changes in how its board of directors is selected. "We will adopt a
transparent, formal process for identifying candidates and appointing new
board members who are wise, capable, and committed to the FSF's mission. We
will establish ways for our supporters to contribute to the discussion. We
will require all existing board members to go through this process as soon
as possible, in stages, to decide which of them remain on the
board."
Meanwhile, numerous community members have posted an open letter calling for
the resignation of the entire Free Software Foundation board of directors
after the announcement that Richard Stallman would be returning. The Free
Software Foundation Europe has made its
disapproval known, as has the Electronic
Frontier Foundation. The Debian project has started
discussing a general resolution affirming its support for the open
letter. Various other organizations have expressed concern as well.
For those who feel differently, there is also an open letter in support
of Stallman's return to the FSF.
corbet
4 év 4 hónap óta
Greg Kroah-Hartman has announced the release of
5.10.26—delayed from the
large batch on March 24—with the usual
important fixes throughout the kernel tree,
and
5.11.10, which just contains some relatively
minor fixes: "This is a 'quick revert' of some 5.11.9 commits that
caused noisy warnings to
show up in the kernel log of some systems. If you do not have this issue, or
are not bothered by these messages, no need to upgrade."
jake
4 év 4 hónap óta
Security updates have been issued by Debian (firefox-esr and lxml), Fedora (jasper), openSUSE (gnutls, hawk2, ldb, libass, nghttp2, and ruby2.5), Oracle (pki-core:10.6), Red Hat (firefox and thunderbird), SUSE (evolution-data-server, ldb, python3, and zstd), and Ubuntu (ldb, linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm, linux-oracle, linux-signed, linux-snapdragon, and linux, linux-lts-xenial).
jake
4 év 4 hónap óta
Open Collective has
put out an
announcement describing its "Funds for Open Source" initiative, which
is aimed at making it easy for corporations to fund the work of individual
developers. "Big companies call the process for paying for stuff
'procurement'. It’s often pretty involved, with contracts, invoices,
purchasing order numbers, and bureaucracy—a painful thing to go through
repeatedly for small amounts. It's practically a blocker. It is so much
simpler and more practical to ask corporations to make one large payment,
to one vendor. Make it easy and companies will invest more."
corbet
4 év 4 hónap óta
The second edition of “
Is Parallel Programming Hard, And, If So, What Can You Do About It?” is now available. I have no plans to create a dead-tree version, but I have no objection to others doing so, whether individually or in groups.
Big-animal changes over the
First Edition include:
- A full rewrite of the memory-barriers section, which is now its own chapter. This new chapter includes discussion of the Linux-kernel memory model, courtesy of Akira Yokosawa, who kindly pulled in the LWN article.
- A number of new tools have been added to the formal-verification chapter.
- A new section on SMP real-time programming.
- The “Tools of the Trade” chapter has been dragged kicking and screaming into the 2020s, courtesy of Akira Yokosawa, Junchang Wang, and Slavomir Kaslev.
- Hyperlinking between quizzes and answers, courtesy of Paolo Bonzini and Akira Yokosawa.
- Improved formatting and build system, courtesy of Akira Yokosawa.
- Bibliographic facelift, courtesy of Stamatis Karnouskos and Akira Yokosawa.
- Grammatical fixes from a great many people, but especially from translators SeongJae Park and Motohiro Kanda.
- Several new cartoons.
- Performance results from a system with hundreds of CPUs, courtesy of my employer, Facebook.
- Substantial updates pretty much everywhere else. (Yes, this might be the first time in a long time that I read through the entire book. Why do you ask?)
Contributors include Akira Yokosawa; SeongJae Park; Junchang Wang; Borislav Petkov; Stamatis Karnouskos; Palik, Imre; Paolo Bonzini; Praveen Kumar; Tobias Klauser; Andreea-Cristina Bernat; Balbir Singh; Bill Pemberton; Boqun Feng; Emilio G. Cota; Namhyung Kim; Andrew Donnellan; Dominik Dingel; Igor Dzreyev; Pierre Kuo; Yubin Ruan; Chris Rorvick; Dave; Mike Rapoport; Nicholas Krause; Patrick Marlier; Patrick Yingxi Pan; Slavomir Kaslev; Zhang, Kai; and Zygmunt Bazyli Krynicki. On behalf of all who read this book, I thank you all for all you did to help make this second edition a reality!
4 év 4 hónap óta
The LWN.net Weekly Edition for March 25, 2021 is available.
corbet
4 év 4 hónap óta
In the latest of Swift numbers: talked to someone today who mentioned that they have 1,025,311,000 objects, or almost exactly a billion. They are spread over only 480 disks. That is, if my arithmetic is correct, 2,000 times smaller than Amazon S3 was in 2013. But hey, not everyone is S3. And they aren't having any particular problems, things just work.
4 év 4 hónap óta
Enumerated types or "enums" are a feature of many languages, including
Python; enums provide a convenient way to collect up a bunch of related
symbols that (typically) evaluate to integer values. The canonical example
would seem to be for colors, at least for demonstration purposes, but there are
others, especially for handling "magic" constants from source likes POSIX
or the host operating system. A recent thread on the python-ideas mailing list discusses
different ways to add a new feature to enums—seven years after they were
added to the standard library as
part of
Python 3.4.
jake
4 év 4 hónap óta
The
WireGuard VPN tunnel is a
fast and easy-to-use solution for those who need or want a secure tunnel
for their traffic. The project has been around since 2016, but it has had a
somewhat circuitous route into Linux; it was merged for the 5.6
kernel, which was released in March 2020. Getting into Linux required
WireGuard developer Jason A. Donenfeld to
acquiesce to having WireGuard use some of the
existing kernel crypto primitives, rather than merging his
Zinc crypto library. Some of the same
tensions that were seen in that process seem to be cropping up again in the more
recent efforts to add WireGuard support to several BSD kernels.
jake
4 év 4 hónap óta
The GNOME 40 release is out. "It brings new design for the Activities overview and improved support for
input with Compose sequences and keyboard shortcuts, among many other
things.
Improvements to core GNOME applications include a redesigned Weather
application, information popups in Maps, better tabs in Web, and many
more." See
the GNOME 40 page
and
the release
notes for details.
corbet
4 év 4 hónap óta
ris
4 év 4 hónap óta
Security updates have been issued by Debian (imagemagick and squid), Fedora (jasper and kernel), Red Hat (pki-core), SUSE (gnutls, go1.15, go1.16, hawk2, jetty-minimal, libass, nghttp2, openssl, ruby2.5, sudo, and wavpack), and Ubuntu (linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke-5.3, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-hwe, linux-hwe-5.4, linux-hwe-5.8, linux-kvm, linux-oem-5.10, linux-oem-5.6, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4, linux-raspi2-5.3).
ris
4 év 4 hónap óta
Just saving it from LinkedIn:
The real difference between SQL-based (and other relational databases) and NoSQL glorified KV stores is the presence of algebraic structure (i.e. Codd algebra). Algebra is basically all about transformations between equivalent expressions to arrive to a desireable form (i.e. simplified, or factorized, or whatever the goal is). These transformations have another name: optimizations.
Basically, when you have a real SQL database, you have ability to optimize execution plans. Which could easily yield orders of magnitude of improvement in performance.
(And, yes, modern relational databases (i.e. Snowflake) do internally convert semi-structured data into tabular form so that the optimizations are applicable to these as well).
If I had something to say about this, it would be something about stable, dependable performance having a value of its own. That is why TokyoCabinet was such a revelation and prompted the NoSQL revolution, which later ended with Mongo and reaction, like any revolution. But this is not my field, so let's just save it for future reference.
4 év 4 hónap óta
Firefox 87 has
been
released. This version introduces
SmartBlock, "a new intelligent tracker blocking mechanism for Firefox Private Browsing and Strict Mode."
Firefox ESR 78.9 has also been
released with the usual set of fixes.
ris
4 év 4 hónap óta
Security updates have been issued by Debian (dnsmasq, libmediainfo, and mariadb-10.1), Fedora (dotnet5.0, moodle, and radare2), Mageia (kernel and kernel-linus), Oracle (python27:2.7, python36:3.6, and python38:3.8), Red Hat (pki-core:10.6), and Ubuntu (privoxy).
ris
4 év 4 hónap óta
The kernel's memory-management subsystem is built upon many concepts, one
of which is called "copy on write", or "COW".
The idea behind COW is conceptually simple, but its
details are tricky and its past is troublesome. Any change to its
implementation can have unexpected consequences and cause subtle breakage
for existing workloads. So it is somewhat surprising that last year we saw
two major changes the kernel's COW code; less surprising is the fact that,
both times, these changes had unexpected consequences and broke things.
Some of the resulting problems are still not fixed
today, almost ten months after the first change, while the original reason
for the changes — a security vulnerability — is also not fully fixed. Read
on for a description of COW, the vulnerability, and the initial fix; the
concluding article in the series will describe the complications that arose
thereafter.
corbet
4 év 4 hónap óta
Security updates have been issued by Arch Linux (chromium, ffmpeg, flatpak, git, gnutls, minio, openssh, opera, and wireshark-qt), Debian (cloud-init, pygments, and xterm), Fedora (flatpak, glib2, kernel, kernel-headers, kernel-tools, pki-core, and upx), Mageia (glibc, htmlunit, koji, and python-cairosvg), openSUSE (chromium, connman, froxlor, grub2, libmysofa, netty, privoxy, python-markdown2, tor, and velocity), Oracle (ipa), SUSE (evolution-data-server, glib2, openssl, python3, python36, and wavpack), and Ubuntu (linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm, linux-raspi2, linux-snapdragon, linux-oem-5.10, and pygments).
ris
4 év 4 hónap óta
At the
LibrePlanet conference
over the weekend, Richard Stallman announced that he has returned to the
Free Software Foundation's board of directors.
Video of the announcement is
available, but there is little information beyond that.
corbet
4 év 4 hónap óta
The
fourth 5.12 kernel prepatch is out for
testing. "So I'll just tempt the fates and say that everything looks
pretty normal and this release seems to look good despite the rc1
hiccup."
corbet