[lttng-dev] using --function/--probe

[Bill Trost]

Mathieu wrote:
    * Bill Trost (trost at cloud.rain.com) wrote:
    > Mathieu wrote:
    >     * Bill Trost (trost at cloud.rain.com) wrote:
    >     > ...how do I trace what work is being
    >     > enqueued and run by the kworker threads?
    > 
    >     For this level of details, I think kprobes/kretprobes will not
    >     currently allow you to fetch it. The two options we have are:
    > 
    >     - use static tracepoints. Is there a tracepoint that targets the
    >       information you are looking for ? Try "lttng list -k".
    > 
    > No, I've been capturing all kernel events and haven't seen
    > anything resembling the kworker tracepoints of lttng 0.x.

    LTTng 2.2-rc has a new workqueue instrumentation. Maybe this can fit
    your use-case ?

Hi, Mathieu,

I'd forgotten all about this. We eventually discovered,
as part of investigating the kworkers, that we had a
misconfigured sysctl. When we fixed that, the offending
kwork then disappeared completely -- problem solved.

Thanks for the "blast from the past",
Bill