On Fri, Jan 21, 2011 at 09:43:18AM +0100, Vincent Guittot wrote: > On 20 January 2011 17:11, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote: > > On Thu, Jan 20, 2011 at 09:25:54AM +0100, Vincent Guittot wrote: > >> Please find below a new proposal for adding trace events for cpu hotplug. > >> The goal is to measure the latency of each part (kernel, architecture) > >> and also to trace the cpu hotplug activity with other power events. I > >> have tested these traces events on an arm platform. > >> > >> Changes since previous version: > >> -Use cpu_hotplug for trace name > >> -Define traces for kernel core and arch parts only > >> -Use DECLARE_EVENT_CLASS and DEFINE_EVENT > >> -Use proper indentation > >> > >> Subject: [PATCH] cpu hotplug tracepoint > >> > >> this patch adds new events for cpu hotplug tracing > >> * plug/unplug sequence > >> * core and architecture latency measurements > >> > >> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx> > >> --- > >> include/trace/events/cpu_hotplug.h | 117 ++++++++++++++++++++++++++++++++++++ > > > > Note we can't apply new tracepoints if they are not inserted in the code. > > I agree, i just want to have 1st feedbacks on the tracepoint interface > before providing a patch which inserts the trace in the code. > > > > >> +DEFINE_EVENT(cpu_hotplug, cpu_hotplug_arch_wait_die_start, > >> + > >> + TP_PROTO(unsigned int cpuid), > >> + > >> + TP_ARGS(cpuid) > >> +); > >> + > >> +DEFINE_EVENT(cpu_hotplug, cpu_hotplug_arch_wait_die_end, > >> + > >> + TP_PROTO(unsigned int cpuid), > >> + > >> + TP_ARGS(cpuid) > >> +); > > > > What is wait die, compared to die for example? > > > > The arch_wait_die is used to trace the process which waits for the cpu > to die (__cpu_die) and the arch_die is used to trace when the cpu dies > (cpu_die) I still can't find the difference. Having: trace_cpu_hotplug_arch_die_start(cpu) __cpu_die(); trace_cpu_hotplug_arch_die_end(cpu) Is not enough to get both the information that a cpu dies and the time took to do so? -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
