We are pleased to announce that the Performance and Scalability Microconference has been accepted into the 2021 Linux Plumbers Conference.

All parts of the Linux ecosystem, kernel and userspace, should account for performance and scalability. The purpose of this microconference is for developers from different projects to meet and collaborate, as the entire stack must perform well for the user to see good results. Because performance and scalability are very generic topics, this microconference focuses on issues that may also be addressed in other, more specific sessions.

The structure will be similar to what was followed in previous years, including topics such as synchronization primitives, bottlenecks in memory management, testing/validation, lockless algorithms and RCU, among others.

Here are some of the outcomes from the last time the event was held in 2018:

• With feedback from the audience, Daniel Jordan was able to get the first steps of his project, formerly known as ktask to parallize CPU-intensive work, merged in mainline as part of the padata parallel execution mechanism. Deferred struct page init is now parallelized on x86 systems.
• During Boqun Feng’s topic on workqueues and CPU hotplug, the audience concluded that the problem under discussion was actually not an issue and a stale comment had misled the community, so a follow-on patch removed part of the initial fix.
• In response to a question from the audience, Mike Kravetz proposed aligning addresses returned from mmap(MAP_ANONYMOUS) calls of at least THP size on THP boundaries, resulting in an RFC patch discussion.

This year’s topics tentatively include:

• Seamless hypervisor update with IOMMU-type-agnostic, directly-attached devices and virtual functions.  Related projects are VMM Fast Restart, PKRAM, and MMU enabled kexec relocation for arm64.
• Performance characteristics of RT spinlocks.
• Accounting CPU-intensive kernel threads in the CPU controller via remote charging (thread 1, thread 2, thread 3).
• Design discussion and performance characteristics of Maple Tree (lwn article).
• mmap_sem contention in procfs (test code, gitweb).
• NUMA-aware spinlocks: (series, lwn article).
• futex2: attempts to tackle the performance limitations of the single NUMA node hash table.
• Batching optimizations in the internals of get_user_pages() and put_user_pages().
• Fast kdump for embedded devices.

Come and join us in the discussion of improving performance and scalability of your system.

We hope to see you there.