Description
Core counts keep rising, and that means that the Linux kernel continues to encounter interesting performance and scalability issues. Which is not a bad thing, since it has been fifteen years since the ``free lunch'' of exponential CPU-clock frequency increases came to an abrupt end. During that time, the number of hardware threads per socket has risen sharply, approaching 100 for some high-end implementations. In addition, there is much more to scaling than simply larger numbers of CPUs.
Proposed topics for this microconference include optimizations for mmap_sem range locking; clearly defining what mmap_sem protects; scalability of page allocation, zone->lock, and lru_lock; swap scalability; variable hotpatching (self-modifying code!); multithreading kernel work; improved workqueue interaction with CPU hotplug events; proper (and optimized) cgroup accounting for workqueue threads; and automatically scaling the threshold values for per-CPU counters.
We are also accepting additional topics. In particular, we are curious to hear about real-world bottlenecks that people are running into, as well as scalability work-in-progress that needs face-to-face discussion.
Huge pages are essential to addressing performance botttlenecks
since the base page sizes are not changing while the amount of memory is
ever increasing. Huge pages can address TLB misses but also memmory
overhead in the Linux kernel that arises through page faults and other
compute intensive processing of small pages. Huge pages are required
with contemporary high speed NVME ssds to reach...
The mmap_sem has long been a contention point in the memory management
subsystem. In this session some mmap_sem related topics will be
discussed. Some optimization has been merged by the upstream kernel to
solve holding mmap_sem for write for excessive period of time in
munmap path by downgrading write mmap_sem to read. And, some
optimization are under discussion on the mailing list, i.e....
Welcome to scalability microconference
