On Fri, Mar 2, 2018 at 10:41 AM, Du, Changbin <changbin...@intel.com> wrote: >> >> That rather isn't the case if negative values are ever passed to the >> >> tracepoint, right? >> >> >> > yes. >> >> Which seems to be the reason why you want to make this change, isn't it? >> >> >> > yes, to improve readability. >> > >> >> So maybe fix the code using the tracepoint(s) to avoid passing >> >> negative values to it(them)? >> > For cpu_idle event, [0, CPUIDLE_STATE_MAX) are used to index the idle >> > state arrary, >> > so I think a appropriate value for PWR_EVENT_EXIT is -1 (defined in >> > include/trace/events/power.h). >> > Or do you have a better idea? Thanks! >> >> Sorry, I'm not sure what you mean. >> >> I'm saying that the code using the CPU PM tracepoints is not expected >> to pass -1 as the CPU number to them. IOW, neither -1 nor its UL >> representation should ever appear in the output of these tracepoints. >> If that happens, it is a problem with the code using the tracepoints >> which needs to be fixed. Users should not see any of these values. > > This patch only changed 'state' field but cpuid. For cpu_idle event, 'state' > is > singned value, but for cpu_frequency it is unsinged. > The cpuid is always unsinged value. So no one passes -1 as CPU number.
You are right, 'state' not 'cpuid', sorry. Negative 'state' should not be passed to these tracepoints too, though.
