Messages in this thread | | | Date | Fri, 13 May 2022 16:21:43 +0200 | From | Juri Lelli <> | Subject | [ANNOUNCE] CFP: CPU Isolation Microconference - Linux Plumbers Conference 2022 |
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CPU Isolation can be considered as an holistic functionality that stems from a close combination of several kernel and userspace components working together to shield workloads with extreme latency or performance requirements from interruptions (also known as Operating System noise). An example of such type of workloads are DPDK (Data Plane Development Kit) use cases (Telco/5G) where even the shortest interruption (e.g., a few microseconds to service an IPI) can cause packet losses, eventually leading to exceeding QoS requirements.
Despite considerable improvements in the last few years towards implementing full CPU Isolation (nohz_full, rcu_nocb, isolcpus, etc.), a certain amount of issues remain to be addressed, as it is still relatively simple to highlight sources of OS noise just by running synthetic workloads mimicking polling (always running) type of application similar to the ones mentioned above.
Recently, improvements and discussions about CPU isolation features have been made and discussed in LKML [1,2,3], and tools such as osnoise tracer and rtla osnoise [4,5] improved the CPU isolation analysis. Nevertheless, this is an ongoing process, and discussions are needed to speed up solutions for existing discussions and improve the existing tools and methods.
With this microconference we thus want to get together to discuss open problems, most notably: how to improve the identification of OS noise sources (expanding runtime tracing and/or code inspection tools), how to track them publicly (repo/DB) and how to tackle the sources of noise that have already been identified (e.g, [1,2,3]).
A non exhaustive list of potential topics is:
- OS noise profiling (format and public DB for the community) - Tracing to detect OS noise: the rtla osnoise tracer and what it’s missing TLB/icache flush deferral [1] - Extend cpuset v2 cpu partition feature to replace isolcpus kernel cmdline - rt-trace-bpf tool - Task isolation - smp_call_function API improvements
If you are interested in participating in this microconference and have topics to propose, please use the LPC CfP process [6], and select "CPU Isolation MC" for the "Track".
The submission deadline is June 30.
Come and join us in the discussion, we hope to see you there!
In case of doubts, feel free to contact the MC Leads:
Juri Lelli <juri.lelli@redhat.com> Daniel Bristot de Oliveira <bristot@redhat.com>
refs. 1 - https://lore.kernel.org/all/20210929151723.162004989@infradead.org/ 2 - https://lore.kernel.org/lkml/20220315153132.717153751@fedora.localdomain/ 3 - https://lore.kernel.org/lkml/20211103170512.2745765-1-nsaenzju@redhat.com/ 4 - https://www.kernel.org/doc/html/latest/trace/osnoise-tracer.html 5 - https://www.kernel.org/doc/html/latest/tools/rtla/rtla-osnoise.html 6 - https://lpc.events/event/16/abstracts/
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