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A processor's translation lookaside buffer (TLB) caches the mappings from
virtual to physical addresses. Looking up virtual addresses is expensive,
so good performance often depends on making the best use of the TLB. In
the memory-management track of the 2017 Linux Storage, Filesystem, and
Memory-Management Summit, Mike Kravetz described a SPARC processor feature
that can improve TLB performance and explored ways in which that feature
could be supported.
of the Kubernetes orchestration system is available. "In
this release the community’s focus is on scale and automation, to help you
deploy multiple workloads to multiple users on a cluster. We are announcing
that 5,000 node clusters are supported. We moved dynamic storage
provisioning to stable. Role-based access control (RBAC), kubefed, kubeadm,
and several scheduling features are moving to beta. We have also added
intelligent defaults throughout to enable greater automation out of the
Google has announced
the launch of opensource.google.com
. "Today, we’re launching opensource.google.com, a new website for Google Open Source that ties together all of our initiatives with information on how we use, release, and support open source.
This new site showcases the breadth and depth of our love for open source. It will contain the expected things: our programs, organizations we support, and a comprehensive list of open source projects we've released. But it also contains something unexpected: a look under the hood at how we "do" open source."
When the transparent huge page feature was added to the kernel, it only
supported anonymous (non-file-backed) memory. In 2016, support for huge pages in the page cache
added, but only the tmpfs filesystem was supported. There is interest in
expanding support to other filesystems, since, for some workloads, the
performance improvement can be significant. Kirill Shutemov led the only
session that combined just the filesystem and memory-management tracks at
the 2017 Linux Storage, Filesystem, and Memory-Management Summit in a
discussion of adding huge-page support to the ext4 filesystem.
Security updates have been issued by Debian (eject, gst-plugins-bad1.0, gst-plugins-base1.0, gst-plugins-good1.0, gst-plugins-ugly1.0, gstreamer1.0, php5, and tiff), Fedora (kernel), Gentoo (curl, deluge, libtasn1, and xen-tools), Mageia (mbedtls, putty, and roundcubemail), openSUSE (dbus-1, gegl, mxml, open-vm-tools, partclone, qbittorrent, tcpreplay, and xtrabackup), and Ubuntu (eject, gst-plugins-base0.10, gst-plugins-base1.0, and gst-plugins-good0.10, gst-plugins-good1.0).
DAX is the mechanism that enables direct access to files stored in
persistent memory arrays without the need to copy the data through the page
cache. At the 2017 Linux Storage, Filesystem, and Memory-Management
Summit, Ross Zwisler led a plenary session on the future of DAX. Development in
this area offers a number of interesting trade-offs between data safety and
enabling the highest performance.
DragonFly BSD 4.8 has been released
version 4.8 brings EFI boot support in the installer, further speed
improvements in the kernel, a new NVMe driver, a new eMMC driver, and Intel
video driver updates." DragonFly is an independent BSD variant,
perhaps best known for the HAMMER filesystem.
The Free Software Foundation has announced
of the 2016 Free Software Awards. The Award for Projects
of Social Benefit went to SecureDrop
and the Award for the Advancement of Free Software went to Alexandre Oliva
. "SecureDrop is an anonymous whistleblowing platform used by major news organizations and maintained by Freedom of the Press Foundation. Originally written by the late Aaron Swartz with assistance from Kevin Poulsen and James Dolan, the free software platform was designed to facilitate private and anonymous conversations and secure document transfer between journalists and sensitive sources."
Stable kernels 4.10.6
, and 4.4.57
have been released. All of them
contain important fixes and users should upgrade.
Security updates have been issued by Debian (apt-cacher, jbig2dec, libplist, python3.2, tnef, and xrdp), Fedora (firefox, mbedtls, and sane-backends), Mageia (flash-player-plugin, freetype2, glibc, kernel, kernel-linus, kernel-tmb, libquicktime, libwmf, and tnef), and Ubuntu (thunderbird).
kernel prepatch is out for
testing. "So on the whole things look fine. There's changes all
over, and in mostly the usual proportions. Some core kernel code shows up
in the diffstat slightly more than it usually does - we had an audit fix
and a bpf hashmap fix, but on the whole it all looks very regular."
In the memory-management subsystem, the term "mapping" refers to the
connection between pages in memory and their backing store — the file that
represents them on disk. One of the fundamental assumptions in the
kernel is that a given page in the page cache belongs to exactly one mapping.
But, as Miklos Szeredi explained in a plenary session at the 2017 Linux
Storage, Filesystem, and Memory-Management Summit, there are situations
where it would be desirable to associate the same page with multiple
mappings. Achieving this goal may not be easy, though.
Click below (subscribers only) for continuing coverage from LSFMM 2017
The Eudyptula Challenge
series of programming exercises for the Linux kernel. It starts from a
very basic "Hello world" kernel module, moves up in complexity to getting
patches accepted into the main kernel. The challenge
will be closed to new participants in a few months, when 20,000 people have
signed up. LWN covered
the Eudyptula Challenge in May 2014,
when it was fairly new. At this time over 19,000 people have signed up and
only 149 have finished.
Security updates have been issued by Arch Linux (libpurple), Debian (audiofile, cgiemail, and imagemagick), Fedora (cloud-init, empathy, and mupdf), Mageia (firefox and thunderbird), Scientific Linux (icoutils and openjpeg), Slackware (mcabber and samba), and Ubuntu (eglibc).
Back in 2015, the OpenSSL project announced
intent to move away from its rather quirky license. Now it has announced
change is moving forward
. "After careful review, consultation
with other projects, and input from the Core Infrastructure Initiative and
legal counsel from the SFLC, the OpenSSL team decided to relicense the code
under the widely-used ASLv2." It is worth noting that this change
and the way it is being pursued are not universally popular, in the OpenBSD camp, at least
Laszlo Agocs takes
at improvements to the basic OpenGL enablers that form the
foundation of Qt Quick and the optional OpenGL-based rendering path of
QPainter in Qt 5.9. "As
, such shader programs will attempt to cache the program
binaries on disk using GL_ARB_get_program_binary
or the standard equivalents in OpenGL ES 3.0. When no support is provided
by the driver, the behavior is equivalent to the non-cached case. The files
are stored in the global or per-process cache location
, whichever is writable. The result is a nice boost in performance when a program is created with the same shader sources next time."
Security updates have been issued by Debian (audiofile, jhead, libxslt, samba, suricata, and wordpress), Fedora (openslp), Mageia (icoutils, kdelibs4, and virtualbox), Oracle (icoutils and openjpeg), Red Hat (icoutils and openjpeg), and Ubuntu (audiofile, git, and samba).
The LWN.net Weekly Edition for March 23, 2017 is available.
GitLab 9.0 has been released
with many new features and improvements. "In the last several releases, GitLab has transformed how development teams get from idea to production. In just a few minutes, you can deploy GitLab to a container scheduler, add CI/CD with auto deployed review apps, utilize ChatOps, and analyze your cycle time. With 9.0 you can now watch your deploys with deploy boards and monitor application performance with Prometheus."
The NTPsec Project has announced the 0.9.7 release of NTPsec, with
assistance from the Mozilla Foundation's "Secure Open Source" initiative.
NTPsec is an implementation of the Network Time Protocol (NTP).
"NTPsec 0.9.7 incorporates significant improvements in security, accuracy,
precision, visualization, and usability, with assistance, contributions,
and audits provided by infosec researchers and other technical contributors.
For this release, the NTPsec Project worked particularly closely with the
Mozilla Foundation's "Secure Open Source" initiative, who funded an infosec
audit, and with Cure53.de, who provided the audit."