All posts by corbet

Kernel prepatch 6.15-rc6

Post Syndicated from corbet original https://lwn.net/Articles/1020816/

Linus has released 6.15-rc6 for testing.

Everything still looks fairly normal – we’ve got a bit more commits
than we did in rc5, which isn’t the trend I want to see as the
release progresses, but the difference isn’t all that big and it
feels more like just the normal noise in timing fluctuation in pull
requests of fixes than any real signal.

So I won’t worry about it. We’ve got another two weeks to go in the
normal release schedule, and it still feels like everything is on
track.

[$] A kernel developer plays with Home Assistant: general impressions

Post Syndicated from corbet original https://lwn.net/Articles/1017720/

Those of us who have spent our lives playing with computers naturally see
the appeal of deploying them though the home for both data acquisition and
automation. But many of us who have watched the evolution of the
technology industry are increasingly unwilling to entrust critical
household functions to cloud-based servers run by companies that may not
have our best interests at heart. The Apache-licensed Home Assistant project offers a
welcome alternative: locally controlled automation with free software.
This two-part series covers roughly a year of Home Assistant use, starting
with a set of overall observations about the project.

Fitti: Waiting for Postgres 18: Accelerating Disk Reads with Asynchronous I/O

Post Syndicated from corbet original https://lwn.net/Articles/1020452/

Lukas Fitti writes in detail
on the pganalyze blog about the asynchronous I/O capability coming with the
PostgreSQL 18 release.

Asynchronous I/O delivers the most noticeable gains in cloud
environments where storage is network-attached, such as Amazon EBS
volumes. In these setups, individual disk reads often take multiple
milliseconds, introducing substantial latency compared to local
SSDs.

With traditional synchronous I/O, each of these reads blocks query
execution until the data arrives, leading to idle CPU time and
degraded throughput. By contrast, asynchronous I/O allows Postgres
to issue multiple read requests in parallel and continue processing
while waiting for results. This reduces query latency and enables
much more efficient use of available I/O bandwidth and CPU cycles.

The state of SSL stacks

Post Syndicated from corbet original https://lwn.net/Articles/1020309/

Willy Tarreau and William Lallemand have posted an extensive white
paper
examining the landscape of the available SSL implementations.

OpenSSL 3.0 performs significantly worse than alternative SSL
libraries, forcing organizations to provision more hardware just to
maintain existing throughput. This raises important questions about
performance, energy efficiency, and operational costs.

Examining alternatives—BoringSSL, LibreSSL, WolfSSL, and
AWS-LC—reveals a landscape of trade-offs. Each offers different
approaches to API compatibility, performance optimization, and QUIC
support. For developers navigating the modern SSL ecosystem,
understanding these trade-offs is crucial for optimizing
performance, maintaining compatibility, and future-proofing their
infrastructure.

The end of the USENIX Annual Technical Conference

Post Syndicated from corbet original https://lwn.net/Articles/1020306/

On the 50th anniversary of the USENIX organization, its flagship Annual
Technical Conference (ATC) is coming
to an end
.

For the past two decades, as more USENIX conferences have joined
the USENIX calendar by focusing on specific topics that grew out of
ATC itself, attendance at ATC has steadily decreased to the point
where there is no longer a critical mass of researchers and
practitioners joining us. Thus, after many years of experiments to
adapt this conference to the ever-changing tech landscape and
community, the USENIX Board of Directors has made the difficult
decision to sunset USENIX ATC.

Many important technologies first saw the light of day at this event.

A new AUTOSEL release

Post Syndicated from corbet original https://lwn.net/Articles/1020203/

AUTOSEL is a tool that is used to find kernel patches that should be
considered for backporting into the stable releases. Sasha Levin has announced a new and completely
rewritten version of AUTOSEL for those who would like to play with it.

Unlike the previous version that relied on word statistics and
older neural network techniques, AUTOSEL leverages modern large
language models and embedding technology to provide significantly
more accurate recommendations.

[$] Injecting speculation barriers into BPF programs

Post Syndicated from corbet original https://lwn.net/Articles/1018494/

The disclosure of the Spectre
class of hardware vulnerabilities
created a lot of pain for kernel
developers (and many others). That pain was especially acutely felt in the
BPF community. While an attacker might have to painfully search the kernel
code base for exploitable code, an attacker using BPF can simply write and
load their own speculation gadgets, which is a much more efficient way of
operating. The BPF community reacted by, among other things, disallowing
the loading of programs that may include speculation gadgets. Luis
Gerhorst would like to change that situation with this patch
series
that takes a more direct approach to the problem.

[$] Custom out-of-memory killers in BPF

Post Syndicated from corbet original https://lwn.net/Articles/1019230/

The out-of-memory (OOM) killer has long been a scary and controversial part
of the Linux kernel. It is summoned from some dark place when the system
as a whole (or, more recently, any given control group) is running so low
on memory that further allocations are not possible; its job is to kill off
processes until a sufficient amount of memory has been freed. Roman
Gushchin has found a way to make the OOM killer even scarier: adding the
ability to load
custom OOM killers in BPF
.

[$] LWN.net Weekly Edition for May 1, 2025

Post Syndicated from corbet original https://lwn.net/Articles/1018680/

Inside this week’s LWN.net Weekly Edition:

  • Front: Mailman 2 vulnerabilities; AI in Debian; __nonstring__; Cache-aware scheduling; Freezing filesystems; Socket-level storage; Debugging information; LWN in 2025.
  • Briefs: Debian election; Kali Linux key; OpenBSD 7.7; Firefox 138.0; GCC 15.1; Meson 1.8.0; Valgrind 3.25.0; FSF review; OSI retrospective; Mastodon; Quotes; …
  • Announcements: Newsletters, conferences, security updates, patches, and more.

Albertson: Future of OSL in Jeopardy

Post Syndicated from corbet original https://lwn.net/Articles/1019520/

Lance Albertson writes
that the Oregon State University Open Source Lab, the home of many
prominent free-software projects over the years, has run into financial
trouble:

I am writing to inform you about a critical and time-sensitive
situation facing the Open Source Lab. Over the past several years,
we have been operating at a deficit due to a decline in corporate
donations. While OSU’s College of Engineering (CoE) has generously
filled this gap, recent changes in university funding have led to a
significant reduction in CoE’s budget. As a result, our current
funding model is no longer sustainable and CoE needs to find ways
to cut programs.

Earlier this week, I was informed that unless we secure $250,000 in
committed funds, the OSL will be forced to shut down later this
year.

The conclusion of the FSF board review

Post Syndicated from corbet original https://lwn.net/Articles/1019479/

The Free Software Foundation has announced
the completion of the review of its board of directors; the process
resulted in the reconfirmation of all five sitting board members.

The review examined board members Ian Kelling, Geoffrey Knauth,
Henry Poole, Richard Stallman, and Gerald Sussman. The process
generated detailed philosophical and policy discussions between
board members and the FSF’s global associate members on topics
ranging from the firmness of the Free Software Definition,
developments in machine learning, to the board’s president
position.

How LWN is faring in 2025

Post Syndicated from corbet original https://lwn.net/Articles/1019217/

Just over six months ago, The Economist described the US economy as “the envy of the
world
“. That headline would be unlikely to appear now. The economic
boom referenced in that article feels like a distant memory, markets are
falling, and uncertainty is at an all-time high. Like everybody else, LWN
is affected by the current turbulence in the political and economic
spheres; we expect to get through this period, but there will be some
challenges.