Hírolvasó

Linux Plumbers Conference 2022 is pleased to host the Real-time and Scheduling Microconference

The real-time and scheduling micro-conference joins these two intrinsically connected communities to discuss the next steps together.

Over the past decade, many parts of PREEMPT_RT have been included in the official Linux codebase. Examples include real-time mutexes, high-resolution timers, lockdep, ftrace, RCU_PREEMPT, threaded interrupt handlers and more. The number of patches that need integration has been significantly reduced, and the rest is mature enough to make their way into mainline Linux.

The scheduler is the core of Linux performance. With different topologies and workloads, it is not an easy task to give the user the best experience possible, from low latency to high throughput, and from small power-constrained devices to HPC.

This year’s topics to be discussed include:

• How to scalqe PREEMPT_RT for very-large systems
• Improve overall system partitioning for real-time HPC workloads
• New tools for PREEMPT_RT analysis.
• How do we teach the rest of the kernel developers how not to break PREEMPT_RT?
• The usage of PREEMPT_RT on safety-critical systems: what do we need to do?
• The merge’s status, and how can we resolve the last issues that block the merge.
• Latency nice scheduling feature
• Better support for new processors
• What’s next?

Please come and join us in the discussion of controlling what tasks get to run on your machine and when.

We hope to see you there!

Processor MMIO Stale Data Vulnerabilities are a class of memory-mapped I/O (MMIO) vulnerabilities that can expose data. The sequences of operations for exposing data range from simple to very complex. Because most of the vulnerabilities require the attacker to have access to MMIO, many environments are not affected. System environments using virtualization where MMIO access is provided to untrusted guests may need mitigation. These vulnerabilities are not transient execution attacks. However, these vulnerabilities may propagate stale data into core fill buffers where the data can subsequently be inferred by an unmitigated transient execution attack. Mitigation for these vulnerabilities includes a combination of microcode update and software changes, depending on the platform and usage model.

Three separate CVE numbers have been issued for variants of this vulnerability; more information can be found in this documentation patch. Stable updates containing these fixes are in the review process and should be released shortly.

Back in 2021 when we were planning this conference, everyone warned us that we’d still be doing social distancing and that in-person conferences were likely not to be as popular as they had been, so we lowered our headcount to fit within a socially distanced venue.   Unfortunately the enthusiasm of the plumbers community didn’t follow this conventional wisdom so the available registrations sold out within days of being released.  We’re now investigating how we might expand the venue capacity to accommodate some of the demand for in-person registration, so stay tuned for what we find out.

Hertzbleed takes advantage of our experiments showing that, under certain circumstances, the dynamic frequency scaling of modern x86 processors depends on the data being processed. This means that, on modern processors, the same program can run at a different CPU frequency (and therefore take a different wall time) when computing, for example, 2022 + 23823 compared to 2022 + 24436.

Note that 5.17.15 will be the last release in the 5.17.x stable series.

Total Cookie Protection works by creating a separate “cookie jar” for each website you visit. Instead of allowing trackers to link up your behavior on multiple sites, they just get to see behavior on individual sites. Any time a website, or third-party content embedded in a website, deposits a cookie in your browser, that cookie is confined to the cookie jar assigned to only that website. No other websites can reach into the cookie jars that don’t belong to them and find out what the other websites’ cookies know about you.

See this Software Freedom Conservancy post for more information her life and work.

This is the last year that we will be adhering to our long-standing tradition of extending the deadline by one week. In 2023, we will break from this tradition, so that the refereed-track deadline will be a hard deadline, not subject to extension.

But this is still 2022, and so we are taking this one last opportunity to announce that we are extending the Refereed-Track deadline from the current June 12 to June 19. Again, if you have already submitted a proposal, thank you very much! For the rest of you, there is one additional week in which to get your proposal submitted. We very much look forward to seeing what you all come up with.