Hi, I had the same question in 2013 and the best answer I got was (by David Ahern):
cpu-clock is wall-clock based -- so samples are taken at regular intervals relative to walltime. I believe that task-clock is relative to the task run time. So, samples are taken at regular intervals relative to the process' runtime. David 2015-08-05 14:55 GMT+02:00 Milian Wolff <m...@milianw.de>: > Hello all, > > I was asked by a colleague of mine what the difference between task-clock and > cpu-clock is. I found many similar questions on the web, but none have a final > answer: > > http://stackoverflow.com/questions/23965363/linux-perf-events-cpu-clock-and-task-clock-what-is-the-difference > https://lkml.org/lkml/2010/11/3/373 > > Could someone explain the difference between the two counters for a non-kernel > person? What is a task for that matter? When I compare the counters on test > applications, they deviate only marginally. > > In general, is there hope for more documentation on the individual performance > counters? Perf list shows what's available but has no information whatsoever > about the actual meaning of the counters. It would be excellent to also > explain how to interpret the counter, or in what case you'd want to look at a > given event. > > Thanks > -- > Milian Wolff > m...@milianw.de > http://milianw.de > -- > To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
