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업데이트: 1시간 32분 지남

Git’s Database Internals III: File History Queries (GitHub blog)

수, 2022/08/31 - 11:36오후
The GitHub blog series on how the Git database works continues with this look at file-history queries.

If these history modes usually have the same output, then why wouldn’t we always use --full-history --simplify-merges? The reason is performance. Not only does simplified history speed up the query by skipping a large portion of commits, it also allows iterative output. The simplified history can output portions of the history without walking the entire history. By contrast, the --simplify-merges algorithm is defined recursively starting at commits with no parents. Git cannot output a single result until walking all reachable commits and computing their diffs on the input path. This can be extremely slow for large repositories.


Security updates for Wednesday

수, 2022/08/31 - 10:31오후
Security updates have been issued by Debian (dpdk, net-snmp, php-horde-mime-viewer, php-horde-turba, and webkit2gtk), Fedora (rsync), Oracle (openssl and systemd), Red Hat (booth, kernel, kernel-rt, and openssl), Slackware (vim), SUSE (bluez, java-1_8_0-ibm, postgresql10, and zlib), and Ubuntu (kernel, linux, linux-raspi, linux-aws, and linux-oem-5.14).

[$] Debian to vote on its firmware path

수, 2022/08/31 - 6:26오전
Dealing with the non-free firmware that is increasingly needed to install Debian has been a hot topic for the distribution over the past few months. The problem goes back further still, of course, but Steve McIntyre re-raised the issue in April, which resulted in a predictable lengthy discussion thread on the debian-devel mailing list. Now McIntyre has proposed a general resolution (GR) with the intent of resolving how to give users a way to install the distribution on their hardware while trying to avoid trampling on the "100% free" guarantee in the Debian Social Contract. Finding the right balance is going to be tricky as is shown by the multiple GR options that have been proposed in the discussion.

Sourceware moving to the Software Freedom Conservancy

수, 2022/08/31 - 5:20오전
Sourceware.org has long hosted the repositories for many important free-software projects, including much of the GNU toolchain. Frank Ch. Eigler has posted about some changes coming to Sourceware:

Red Hat has been and continues to be a generous sponsor of the hardware, connectivity, and the very modest employee time it requires. We are glad to report there are zero indications of any change to this commitment. Things are stable, new services are coming online, and users seem to be happy. However, it is always good to think about any future needs.

To protect confidence in the long term future of this hosting service, we have reached out to the Software Freedom Conservancy (SFC) to function as a "fiscal sponsor".


Git’s database internals II: commit history queries (GitHub blog)

수, 2022/08/31 - 5:10오전
The GitHub blog has posted a detailed look at how Git stores the commit history to be able to quickly answer queries.

The commit-graph file provides a location for adding new information to our commits that do not exist in the commit object format by default. The new information that we store is called a generation number. There are multiple ways to compute a generation number, but the most important property we need to guarantee is the following:

If the generation number of a commit A is less than the generation number of a commit B, then A cannot reach B.


Security updates for Tuesday

화, 2022/08/30 - 10:33오후
Security updates have been issued by Debian (thunderbird), Fedora (ctk, dcmtk, OpenImageIO, and varnish-modules), Red Hat (systemd), SUSE (libslirp, open-vm-tools, and opera), and Ubuntu (jupyter-notebook, libsdl1.2, and systemd).

[$] Crash recovery for user-space block drivers

화, 2022/08/30 - 12:10오전
A new user-space block driver mechanism entered the kernel during the 6.0 merge window. This subsystem, called "ublk", uses io_uring to communicate with user-space drivers, resulting in some impressive performance numbers. Ublk has a lot of interesting potential, but the current use cases for it are not entirely clear. The recently posted crash-recovery mechanism for ublk makes it clear, though, that those use cases do exist.

Two stable kernels

월, 2022/08/29 - 11:26오후
Greg Kroah-Hartman has released the 5.19.5 and 5.10.139 stable kernels to fix a problem stemming from an incorrect merge of a patch to the dummy-tools used for building kernels.

Security updates for Monday

월, 2022/08/29 - 11:03오후
Security updates have been issued by Debian (curl, exim4, maven-shared-utils, ndpi, puma, webkit2gtk, and wpewebkit), Fedora (dotnet3.1, firefox, and webkit2gtk3), Mageia (clamav, mariadb, net-snmp, postgresql, python-ldap, and thunderbird), SUSE (freeciv, gnutls, keepalived, libyang, nim, python-Django, and varnish), and Ubuntu (schroot).

Kernel prepatch 6.0-rc3

월, 2022/08/29 - 7:40오전
The 6.0-rc3 kernel prepatch is out for testing.

So as some people already noticed, last week was an anniversary week - 31 years since the original Linux development announcement. How time flies.

But this is not that kind of historic email - it's just the regular weekly RC release announcement, and things look pretty normal.


[$] Toward a better definition for i_version

금, 2022/08/26 - 11:41오후
Filesystems maintain a lot of metadata about the files they hold; most of this metadata is for consumption by user space. Some metadata, though, stays buried within the filesystem and is not visible outside of the kernel. Once such piece of metadata is the file version count, known as i_version. Current efforts to change how i_version is managed — and to make it visible to user space — have engendered a debate on what i_version actually means and what its behavior should be.

Security updates for Friday

금, 2022/08/26 - 11:28오후
Security updates have been issued by Debian (zlib), Fedora (dotnet3.1, firefox, java-1.8.0-openjdk-aarch32, thunderbird, and zlib), Mageia (canna, chromium-browser-stable, dovecot, firefox/nss, freeciv, freetype2, gnutls, kernel, kernel-linus, kicad, ldb/samba/sssd, libgsasl, microcode, nodejs, rsync, thunderbird, and unbound), Oracle (php:7.4 and systemd), Scientific Linux (firefox, rsync, systemd, and thunderbird), Slackware (vim), and SUSE (bluez, gstreamer-plugins-good, java-1_7_1-ibm, java-1_8_0-ibm, kernel, libcroco, postgresql10, postgresql13, python-lxml, and webkit2gtk3).

[$] Ushering out strlcpy()

금, 2022/08/26 - 12:17오전
With all of the complex problems that must be solved in the kernel, one might think that copying a string would draw little attention. Even with the hazards that C strings present, simply moving some bytes should not be all that hard. But string-copy functions have been a frequent subject of debate over the years, with different variants being in fashion at times. Now it seems that the BSD-derived strlcpy() function may finally be on its way out of the kernel.

Stable kernel updates

목, 2022/08/25 - 11:08오후
Greg Kroah-Hartman has released the 5.19.4, 5.15.63, 5.10.138, 5.4.211, 4.19.256, 4.14.291, and 4.9.326 stable kernels. They all contain important fixes throughout the kernel tree; users should upgrade.

Security updates for Thursday

목, 2022/08/25 - 10:56오후
Security updates have been issued by Debian (firefox-esr, libxslt, and open-vm-tools), Fedora (dotnet6.0 and firefox), Oracle (curl, firefox, rsync, and thunderbird), Red Hat (curl, firefox, php:7.4, rsync, systemd, and thunderbird), SUSE (bluez, chromium, freerdp, glibc, gnutls, kernel, postgresql10, raptor, rubygem-rails-html-sanitizer, and spice), and Ubuntu (firefox, linux, linux-kvm, linux-lts-xenial, linux-aws, linux-azure-fde, open-vm-tools, and varnish).

[$] LWN.net Weekly Edition for August 25, 2022

목, 2022/08/25 - 9:53오전
The LWN.net Weekly Edition for August 25, 2022 is available.

[$] From late-bound arguments to deferred computation, part 2

수, 2022/08/24 - 11:16오후
Discussion on PEP 671 ("Syntax for late-bound function argument defaults") has been going on—in fits and starts—since it was introduced last October. The idea is to provide a way to specify the default for a function argument that is evaluated in the scope of the function call, which will allow more concise, and visible, defaults. But there has been a persistent complaint that what the language needs is a more-general deferred computation feature; late-bound defaults would simply fall out as one specific user of the feature. The arrival of a proposal for deferred computation did not really accomplish that goal, however.

The future of NGINX

수, 2022/08/24 - 10:59오후
This blog post on the NGINX corporate site describes the plans for this web server project in the coming year.

For the core NGINX Open Source software, we continue to add new features and functionality and to support more operating system platforms. Two critical capabilities for security and scalability of web applications and traffic, HTTP3 and QUIC, are coming in the next version we ship.


Security updates for Wednesday

수, 2022/08/24 - 10:11오후
Security updates have been issued by Fedora (vim), SUSE (cosign, dpdk, freeciv, gfbgraph, kernel, nim, p11-kit, perl-HTTP-Daemon, python-lxml, and python-treq), and Ubuntu (linux-oem-5.14, open-vm-tools, and twisted).

Firefox 104 released

수, 2022/08/24 - 6:22오전
Version 104 of the Firefox browser has been released. The most interesting new feature, perhaps, is the ability to analyze a web site's power usage — but that feature is not available on Linux.