* Mathieu Desnoyers (mathieu.desnoyers@xxxxxxxxxxxx) wrote: > * Peter Zijlstra (peterz@xxxxxxxxxxxxx) wrote: > > On Thu, 2011-12-01 at 17:04 -0500, Mathieu Desnoyers wrote: > > > * Peter Zijlstra (peterz@xxxxxxxxxxxxx) wrote: > > > > On Thu, 2011-12-01 at 16:41 -0500, Mathieu Desnoyers wrote: > > > > > LTTng needs this symbol to prepend the current task dynamic priority > > > > > value to events (optional context information). > > > > > > > > I absolutely detest exporting such stuff. It propagates the idea that > > > > task prio actually means something. Also, modules really shouldn't care. > > > > > > People debugging their SCHED_FIFO/SCHED_RR applications, as well as > > > users of priority-inheritance futexes, may happen to find this > > > information extremely useful. > > > > > > Just saying... > > > > Right until the moment we go do deadlines.. Anyway, it still doesn't > > make sense, your sched_switch() tracepoint handler gets this > > information, why do you need this export at all? > > If you don't want to trace sched_switch, but just conveniently prepend > this information to all your events, then lttng lets you dynamically > target this extra bit of information. Note that it's not a mandatory > event field: I call those "context" fields that the tracer prepends to > events, as requested by the user. One more point: compudj@thinkos:/proc/204$ cat sched khubd (204, #threads: 1) --------------------------------------------------------- se.exec_start : 3355267.749529 se.vruntime : 113843.899081 se.sum_exec_runtime : 12.820702 nr_switches : 386 nr_voluntary_switches : 385 nr_involuntary_switches : 1 se.load.weight : 1024 policy : 0 prio : 120 clock-delta : 130 So what you are saying is that it is fine to export task_prio to _userspace_, thus making it part of the ABI, but it's not OK to export it to GPL modules ? Weird huh ? Mathieu > > Thanks, > > Mathieu > > > -- > Mathieu Desnoyers > Operating System Efficiency R&D Consultant > EfficiOS Inc. > http://www.efficios.com -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
