LWN.net featured content

[$] Pencil, Pencil, and Pencil

n8willis — 2013-06-18T19:30:59+00:00

An unfortunate drawback to the scratch-your-own-itch development model on which many free software projects depend is that creators can lose interest. Without a maintainer, code gets stale and users are either stranded or simply jump ship to a competing project. If the community is lucky, new developers pick up where the old ones left off, and a project may be revived or even driven to entirely new levels of success. On the other hand, it is also possible for multiple people to start their own forks of the code base, which can muddy the waters in a hurry—as appears to be happening at the moment with the 2D animation tool Pencil. Plenty of people want to see it survive, which has resulted in a slew of individual forks.

[$] Dividing the Linux desktop

corbet — 2013-06-17T17:20:06+00:00

The Ubuntu desktop has been committed to the Unity shell for some time; more recently, Canonical also announced that Ubuntu will be moving over to the new, in-house Mir display server. That decision raised a number of eyebrows at the time, given that most of the desktop Linux community had long since settled on Wayland as its way forward. As time passes, though, the degree to which Canonical is breaking from the rest of the community is becoming increasingly clear. The Linux desktop could never be described as being "unified," but the split caused by projects like Mir and SurfaceFlinger may prove to be more profound than the desktop wars of the past.

[$] LWN.net Weekly Edition for June 13, 2013

corbet — 2013-06-13T01:10:55+00:00

The LWN.net Weekly Edition for June 13, 2013 is available.

[$] A report from pgCon 2013

jake — 2013-06-10T21:15:26+00:00

This year's pgCon, which concluded May 25th, included an unusually high number of changes to the PostgreSQL community, codebase, and development. Contributors introduced multiple new major projects which will substantially change how people use PostgreSQL, including parallel query, a new binary document store type, and pluggable storage. In addition, Tom Lane switched jobs, four new committers were selected, pgCon had the highest attendance ever at 256 registrations, and held its first unconference after the regular conference. Subscribers can click below for the report by guest author Josh Berkus.

[$] Little things that matter in language design

jake — 2013-06-08T00:46:43+00:00

The designers of a new programming language are probably most interested in the big features — the things that just couldn't be done with whichever language they are trying to escape from. So they are probably thinking of the type system, the data model, the concurrency support, the approach to polymorphism, or whatever it is that they feel will affect the expressiveness of the language in the way they want. But there are lots of little things to consider too, and guest author Neil Brown looks at some of them in an article from next week's edition.

LWN.net Weekly Edition for June 6, 2013

corbet — 2013-06-06T01:24:48+00:00

The LWN.net Weekly Edition for June 6, 2013 is available.

Power-aware scheduling meets a line in the sand

corbet — 2013-06-05T18:19:09+00:00

As mobile and embedded processors get more complex — and more numerous — the interest in improving the power efficiency of the scheduler has increased. While a number of power-related scheduler patches exist, none seem all that close to merging into the mainline. Getting something upstream always looked like a daunting task; scheduler changes are hard to make in general, these changes come from a constituency that the scheduler maintainers are not used to serving, and the existence of competing patches muddies the water somewhat. But now it seems that the complexity of the situation has increased again, to the point that the merging of any power-efficiency patches may have gotten even harder.

Trusting upstream

jake — 2013-06-04T19:49:18+00:00

When one is trying to determine if there are compliance problems in a body of source code—either code from a device maker or from someone in the supply chain for a device—the sheer number of files to consider can be a difficult hurdle. A simple technique can reduce the search space significantly, though it does require a bit of a "leap of faith", according to Armijn Hemel. He presented his technique, along with a case study and a war story or two at LinuxCon Japan.

LWN.net Weekly Edition for May 31, 2013

corbet — 2013-05-31T01:21:27+00:00

The LWN.net Weekly Edition for May 31, 2013 is available.

The Linus and Dirk show

jake — 2013-05-30T21:27:52+00:00

Linus Torvalds and Dirk Hohndel sat down at LinuxCon Japan 2013 for a "fireside chat" (sans fire), ostensibly to discuss where Linux is going. While they touched on that subject, the conversation was wide-ranging over both Linux and non-Linux topics, from privacy to diversity and from educational systems to how operating systems will look in 20-30 years. Subscribers can click below for the full story from this week's edition.

Atomic I/O operations

corbet — 2013-05-30T02:48:46+00:00

According to Btrfs developer Chris Mason, tuning Linux filesystems to work well on solid-state storage devices is a lot like working on an old, clunky car. Lots of work goes into just trying to make the thing run with decent performance. Old cars may have mainly hardware-related problems, but, with Linux, the bottleneck is almost always to be found in the software. It is, he said, hard to give a customer a high-performance device and expect them to actually see that performance in their application. Fixing this problem will require work in a lot of areas. One of those areas, supporting and using atomic I/O operations, shows particular potential.

Click below (subscribers only) for the full report from LinuxCon Japan.

Pondering the X client vulnerabilities

corbet — 2013-05-27T22:05:28+00:00

Certain projects are known for disclosing a large number of vulnerabilities at once; such behavior is especially common in company-owned projects where fixes are released in batches. Even those projects, though, rarely turn up with 30 new CVE numbers in a single day. But, on May 23, the X.org project did exactly that when it disclosed a large number of security vulnerabilities in various X client libraries — some of which could be more than two decades old.

Click below (subscribers only) for the full article.

LWN.net Weekly Edition for May 23, 2013

corbet — 2013-05-23T00:40:47+00:00

The LWN.net Weekly Edition for May 23, 2013 is available.

An "enum" for Python 3

jake — 2013-05-22T18:18:32+00:00

Designing an enumeration type (i.e. "enum") for a language may seem like a straightforward exercise, but the recently "completed" discussions over Python's PEP 435 show that it has a few wrinkles. The discussion spanned several long threads in two mailing lists (python-ideas, python-devel) going back to January in this particular iteration, but the idea is far older than that. Subscribers can click below for the full article from this week's edition.

An unexpected perf feature

jake — 2013-05-21T22:10:55+00:00

Local privilege escalations seem to be regularly found in the Linux kernel these days, but they usually aren't quite so old—more than two years since the release of 2.6.37—or backported into even earlier kernels. But CVE-2013-2094 is just that kind of bug, with a now-public exploit that apparently dates back to 2010.

Click below (subscribers only) for LWN's look at this vulnerability.

LWN.net Weekly Edition for May 16, 2013

corbet — 2013-05-16T01:08:56+00:00

The LWN.net Weekly Edition for May 16, 2013 is available.

A look at the PyPy 2.0 release

jake — 2013-05-15T15:31:48+00:00

It's hard to say why, but May appears to be the month where we look in on PyPy. Three years ago, we had a May 2010 introduction to PyPy, followed by an experiment using it in May 2011. This year, the PyPy 2.0 release was made on May 9—that, coupled with our evident tradition, makes for a good reason to look in on this Python interpreter written in Python. Subscribers can click below for our report on the release from this week's edition.

PostgreSQL 9.3 beta: Federated databases and more

jake — 2013-05-14T20:04:15+00:00

In Berkeley, California — the birthplace of PostgreSQL — it's spring: plum and cherry blossoms, courting finches and college students, new plans for the summer, and the first beta release of the database system. Every year, the first beta of the next PostgreSQL version comes out in April or May, for a final release in September. PostgreSQL 9.3 beta 1 was released to the public on May 13th, and contains a couple dozen new features both for database administrators and application developers. Subscribers can click below for a look at some of the new features by guest author Josh Berkus.

LWN.net Weekly Edition for May 9, 2013

corbet — 2013-05-09T01:46:04+00:00

The LWN.net Weekly Edition for May 9, 2013 is available.

(Nearly) full tickless operation in 3.10

corbet — 2013-05-08T15:47:33+00:00

On a typical Linux system, each running CPU will be diverted between 100 and 1000 times each second by the periodic timer interrupt. That interrupt is the CPU's cue to reconsider which process should be running, catch up with read-copy-update (RCU) callbacks, and generally handle any necessary housekeeping. This periodic "tick" can be reasonably compared to the infamous big kernel lock (BKL): it is convenient to have around, but it also has an effect on performance that makes developers wish to abolish it. The key difference might be that getting rid of the timer tick has taken rather longer than was required to eliminate the BKL. The 3.10 kernel will take an important step in that direction, though, with the addition of the "full NOHZ" mode — but a lot of limitations still apply.