út 22. 7. 2025 v 17:30 odesílatel Steven Rostedt <rost...@goodmis.org> napsal: > > On Tue, 22 Jul 2025 09:03:24 +0200 > Tomas Glozar <tglo...@redhat.com> wrote: > > > Of course, this is just an implementational limitation of the timerlat > > tracer. If timerlat had an event (like osnoise's "sample_threshold") > > triggered on threshold overflow and if it is possible to wait on it > > even without BPF, rtla could wait on that for both BPF and non-BPF > > mode instead of what it is currently doing. > > Right. Is this something you may want? >
I don't think it is that important. Non-BPF mode is mostly as a fallback for users of rtla on older kernels which don't have the osnoise:timerlat_sample trace event. Those are (I assume) mostly users of LTS distributions who run newer rtla from a container. Adding a new event wouldn't help in their case. The only users who would benefit from that are those who don't have BPF or libbpf. If there is interest from using low-latency actions on threshold in such settings, I'm not against implementing a threshold overflow tracepoint and supporting it in rtla for triggering actions on threshold. Tomas
