Re: [RFC 00/13] perf: Add perf kwork

[Yang Jihong]

Hello,

On 2022/6/22 22:59, Paul A. Clarke wrote:
> On Mon, Jun 13, 2022 at 05:45:52PM +0800, Yang Jihong wrote:
> > Sometimes, we need to analyze time properties of kernel work such as irq,
> > softirq, and workqueue, such as delay and running time of specific interrupts.
> > Currently, these events have kernel tracepoints, but perf tool does not
> > directly analyze the delay of these events
> >
> > The perf-kwork tool is used to trace time properties of kernel work
> > (such as irq, softirq, and workqueue), including runtime, latency,
> > and timehist, using the infrastructure in the perf tools to allow
> > tracing extra targets
> >
> > test case:
> >
> >    # perf kwork report
> >
> >      Kwork Name                | Cpu  | Total Runtime | Frequency | Max runtime   | Max runtime start   | Max runtime end     |
> >     ---------------------------------------------------------------------------------------------------------------------------
> >      (s)RCU:9                  | 0007 |      3.488 ms |      1258 |      0.145 ms |    3398384.220013 s |    3398384.220157 s |
> >      (s)NET_RX:3               | 0003 |      1.866 ms |       156 |      0.042 ms |    3398385.629764 s |    3398385.629806 s |
> >      (s)TIMER:1                | 0000 |      1.799 ms |       117 |      0.055 ms |    3398385.568033 s |    3398385.568088 s |
> >      (w)0xffff9c66e563ee98     | 0006 |      1.561 ms |         5 |      0.351 ms |    3398384.060021 s |    3398384.060371 s |
>
> What units are used for "Frequency"? It would be helpful to include somewhere.
This refers to the number of event in the trace period.

Thanks，
Jihong
> PC
> .