[Fix up LKML address.] On Thu, Mar 1, 2018 at 3:27 AM, Du, Changbin <changbin...@intel.com> wrote: > Hi, > On Wed, Feb 28, 2018 at 11:27:09AM +0100, Rafael J. Wysocki wrote: >> On Wed, Feb 28, 2018 at 10:20 AM, <changbin...@intel.com> wrote: >> > From: Changbin Du <changbin...@intel.com> >> > >> > The type of state is signed int, convert it to unsigned int looks weird. >> > (-1 become 4294967295) >> > 932.123 power:cpu_idle:state=1 cpu_id=0) >> > 932.125 power:cpu_idle:state=4294967295 cpu_id=0) >> > 932.132 power:cpu_idle:state=1 cpu_id=0) >> > 932.133 power:cpu_idle:state=4294967295 cpu_id=0) >> > >> > Similarly for cpu_frequency as "state=%lu cpu_id=%lu". User need to read >> > the code to understand what 'state' means. >> > >> > No functional change in this patch. >> >> 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.
