| [tracecompass-dev] R: Question about VM tracing with LTTng and Virtual Machine Analysis inside TraceCompass |
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Hi,
Thank you for your help! We tested the branches that you sent; two of them give us errors during the building process.
Cheers,
Dario Faggioli and Emilio Bruno
Da: tracecompass-dev <tracecompass-dev-bounces@xxxxxxxxxxx> per conto di tracecompass developer discussions <tracecompass-dev@xxxxxxxxxxx>
Inviato: lunedì 22 febbraio 2021 17:42 A: tracecompass-dev@xxxxxxxxxxx <tracecompass-dev@xxxxxxxxxxx> Oggetto: Re: [tracecompass-dev] Question about VM tracing with LTTng and Virtual Machine Analysis inside TraceCompass Hi,
>> Here's a presentation from almost 3 years ago on the topic, linking >> to more recent (but still outdated) lttng-tools/ust/modules branches >> [1]. This approach does not require trace synchronization at all. >> > Ah, cool! And thanks again. > > Just from a really quick look, it seems similar to what the ftrace & > trace-cmd developers are doing, in order to achieve the same. From what I saw of ftrace virtual machine tracing (my last look at ftrace vm tracing was more than one year ago), iirc the guest have an agent that sends the events to the host, who sets the timestamp, and that is where they are all collected. Some students did try similar approaches, but the one we are proposing with the lttng branches below still involves taking individual traces on all guests and hosts. > >> The Trace Compass documentation was never updated to link to these, >> as I was hoping they would make it in upstream lttng first and was >> waiting for that. But that never happened, due to lack of interest by >> the community. >> >> If you are interested, I can try to see if I can quickly rebase these >> branches on the latest lttng 2.12, so you can try it out. You could >> also contact the lttng community to see if they have anything in >> their roadmap regarding this feature. >> > Well, if you're up for trying a quick rebase, we are certainly up for > giving whatever you produce a try and test it. So I made a quick rebase, here are the branches that you can use. I tested very very quickly and it seems to work fine, but don't try it in production! lttng-ust: https://github.com/tahini/lttng-ust-1/tree/statedump-notifier-2.12 lttng-tools: https://github.com/tahini/lttng-tools/tree/kvm-2.12 lttng-modules: https://github.com/tahini/lttng-modules/tree/product_uuid On the guests, you don't necessarily need the lttng-ust and lttng-tools branches, unless you want to take UST traces, just lttng-modules is enough there, with lttng-tools 2.12. Additionally, for those traces to work on trace compass Virtual Machine analysis, you need this patch on the incubator: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/122053 If you try it, please let us know how it goes! Cheers, Geneviève _______________________________________________ tracecompass-dev mailing list tracecompass-dev@xxxxxxxxxxx To unsubscribe from this list, visit https://www.eclipse.org/mailman/listinfo/tracecompass-dev |