Longtime
PyPy developer Antonio Cuni has a
lengthy
blog post that describes his talk at the recently completed
2025
CPython
Core Dev Sprint, held at Arm in Cambridge, UK. The talk, entitled
"Tracing JIT and real world Python — aka: what we can learn from PyPy" was
meant to try to pass on some of his experiences "optimizing existing
code for PyPy at a high-frequency trading firm" to the
developers working on the
CPython JIT compiler. His goal was
to raise awareness of some of the problems he encountered:
Until now CPython's performance has been particularly predictable, there are well established "performance tricks" to make code faster, and generally speaking you can mostly reason about the speed of a given piece of code "locally".
Adding a JIT completely changes how we reason about performance of a given program, for two reasons:
- JITted code can be very fast if your code conforms to the heuristics applied by the JIT compiler, but unexpectedly slow(-ish) otherwise;
- the speed of a given piece of code might depend heavily on what
happens elsewhere in the program, making it much harder to reason about
performance locally.
The end result is that modifying a line of code can significantly impact seemingly unrelated code. This effect becomes more pronounced as the JIT becomes more sophisticated.
Cuni also gave a talk on Python performance, which LWN covered, at
EuroPython 2025 in July.
Security updates have been issued by AlmaLinux (grub2 and kernel), Debian (chromium and libxslt), Fedora (chromium, expat, libssh, and webkitgtk), Oracle (avahi, firefox, ImageMagick, kernel, libtpms, and mysql), Red Hat (kernel), SUSE (bird3, expat, kernel, and tiff), and Ubuntu (dpkg, gnuplot, linux, linux-aws, linux-aws-5.15, linux-gcp, linux-gcp-5.15, linux-gke, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-oracle, linux-raspi, linux-riscv-5.15, linux-xilinx-zynqmp, linux, linux-aws, linux-gcp, linux-gcp-6.14, linux-oracle, linux-realtime, linux-riscv, linux-riscv-6.14, linux-aws-fips, linux-fips, linux-gcp-fips, linux-azure, linux-azure-fips, linux-ibm, linux-ibm-6.8, linux-intel-iot-realtime, linux-realtime, linux-oem-6.14, linux-oracle-5.15, linux-realtime-6.14, and python-eventlet).
Version
18 of the PostgreSQL database has been released. Notable
improvements in this release include "skip scan" lookups for
multicolumn B-tree indexes, virtual
generated columns, better text processing, oauth
authentication, and a new asynchronous I/O (AIO) subsystem to improve
performance:
AIO lets PostgreSQL issue multiple I/O requests concurrently instead
of waiting for each to finish in sequence. This expands existing
readahead and improves overall throughput. AIO operations supported in
PostgreSQL 18 include sequential scans, bitmap heap scans, and
vacuum. Benchmarking has demonstrated performance gains of up to 3x in
certain scenarios.
There are, of course, many other improvements and changes; see the
release
notes for full details.
An anonymous reader quotes a report from The Conversation: Twenty-one years after Facebook's launch, Australia's top 25 news outlets now have a combined 27.6 million followers on the platform. They rely on Facebook's reach more than ever, posting far more stories there than in the past. With access to Meta's Content Library (Meta is the owner of Facebook), our big data study analysed more than three million posts from 25 Australian news publishers. We wanted to understand how content is distributed, how audiences engage with news topics, and the nature of misinformation spread. The study enabled us to track de-identified Facebook comments and take a closer look at examples of how misinformation spreads. These included cases about election integrity, the environment (floods) and health misinformation such as hydroxychloroquine promotion during the COVID pandemic. The data reveal misinformation's real-world impact: it isn't just a digital issue, it's linked to poor health outcomes, falling public trust, and significant societal harm. [...]
Our study has lessons for public figures and institutions. They, especially politicians, must lead in curbing misinformation, as their misleading statements are quickly amplified by the public. Social media and mainstream media also play an important role in limiting the circulation of misinformation. As Australians increasingly rely on social media for news, mainstream media can provide credible information and counter misinformation through their online story posts. Digital platforms can also curb algorithmic spread and remove dangerous content that leads to real-world harms. The study offers evidence of a change over time in audiences' news consumption patterns. Whether this is due to news avoidance or changes in algorithmic promotion is unclear. But it is clear that from 2016 to 2024, online audiences increasingly engaged with arts, lifestyle and celebrity news over politics, leading media outlets to prioritize posting stories that entertain rather than inform. This shift may pose a challenge to mitigating misinformation with hard news facts. Finally, the study shows that fact-checking, while valuable, is not a silver bullet. Combating misinformation requires a multi-pronged approach, including counter-messaging by trusted civic leaders, media and digital literacy campaigns, and public restraint in sharing unverified content.
Read more of this story at Slashdot.
An anonymous reader quotes a report from The Guardian: The world's oceans have failed a key planetary health check for the first time, primarily due to the burning of fossil fuels, a report has shown. In its latest annual assessment, the Potsdam Institute for Climate Impact Research said ocean acidity had crossed a critical threshold for marine life. This makes it the seventh of nine planetary boundaries to be transgressed, prompting scientists to call for a renewed global effort to curb fossil fuels, deforestation and other human-driven pressures that are tilting the Earth out of a habitable equilibrium. The report, which follows earlier warnings about ocean acidity, comes at a time of recordbreaking ocean heat and mass coral bleaching.
Oceans cover 71% of the Earth's surface and play an essential role as a climate stabilizer. The new report calls them an "unsung guardian of planetary health", but says their vital functions are threatened. The 2025 Planetary Health Check noted that since the start of the industrial era, oceans' surface pH has fallen by about 0.1 units, a 30-40% increase in acidity, pushing marine ecosystems beyond safe limits. Cold-water corals, tropical coral reefs and Arctic marine life are especially at risk. This is primarily due to the human-caused climate crisis. When carbon dioxide from oil, coal and gas burning enters the sea, it forms carbonic acid. This reduces the availability of calcium carbonate, which many marine organisms depend upon to grow coral, shells or skeletons.
Near the bottom of the food chain, this directly affects species like oysters, molluscs and clams. Indirectly, it harms salmon, whales and other sea life that eat smaller organisms. Ultimately, this is a risk for human food security and coastal economies. Scientists are concerned that it could also weaken the ocean's role as the planet's most important heat absorber and its capacity to draw down 25-30% of the carbon dioxide in the atmosphere. Marine life plays an important role in this process, acting as a "biotic bump" to sequester carbon in the depths. In the report, all of the other six breached boundaries -- climate change, biosphere integrity, land system change, freshwater use, biogeochemical flows, and novel entities -- showed a worsening trend. But the authors said the addition of the only solely ocean-centerd category was a alarming development because of its scale and importance.
Read more of this story at Slashdot.