Messages in this thread | | | Subject | Re: [RFC 00/13] perf: Add perf kwork | From | Yang Jihong <> | Date | Fri, 24 Jun 2022 09:26:56 +0800 |
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Hello,
On 2022/6/23 22:25, Paul A. Clarke wrote: > On Thu, Jun 23, 2022 at 09:02:45AM +0800, Yang Jihong wrote: >> 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. > > I see. I suggest changing the column heading to say that. > "Count", "Number of Events", "Occurrences", something like that. > > "Frequency" is a count-per-time-unit, like hertz, which doesn't > match well here.
OK, I'll fix in next version.
Thanks, Jihong
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