On Mon, Jun 17, 2019 at 09:41:37PM +0800, Zhang Rui wrote: > After S3 suspend/resume, "perf stat -I 1000 -e power/energy-pkg/ -a" > reports an insane value for the very first sampling period after resume > as shown below. > > 19.278989977 2.16 Joules power/energy-pkg/ > 20.279373569 1.96 Joules power/energy-pkg/ > 21.279765481 2.09 Joules power/energy-pkg/ > 22.280305420 2.10 Joules power/energy-pkg/ > 25.504782277 4,294,966,686.01 Joules power/energy-pkg/ > 26.505114993 3.58 Joules power/energy-pkg/ > 27.505471758 1.66 Joules power/energy-pkg/ > > Fix this by resetting the counter right after resume.
Cute... > +#ifdef CONFIG_PM > + > +static int perf_rapl_suspend(void) > +{ > + int i; > + > + get_online_cpus(); > + for (i = 0; i < rapl_pmus->maxpkg; i++) > + rapl_pmu_update_all(rapl_pmus->pmus[i]); > + put_online_cpus(); > + return 0; > +} > + > +static void perf_rapl_resume(void) > +{ > + int i; > + > + get_online_cpus(); > + for (i = 0; i < rapl_pmus->maxpkg; i++) > + rapl_pmu_restart_all(rapl_pmus->pmus[i]); > + put_online_cpus(); > +} What's the reason for that get/put_online_cpus() here ?