#define PWR_EVENT_EXIT -1
 
 struct per_pid;
+struct power_event;
 
 struct timechart {
        struct perf_tool        tool;
        struct per_pid          *all_data;
+       struct power_event      *power_events;
        int                     proc_num;
        unsigned int            numcpus;
        u64                     min_freq,       /* Lowest CPU frequency seen */
        const char *backtrace;
 };
 
-static struct power_event    *power_events;
 static struct wake_event     *wake_events;
 
 struct process_filter {
        cpus_cstate_state[cpu] = state;
 }
 
-static void c_state_end(int cpu, u64 timestamp)
+static void c_state_end(struct timechart *tchart, int cpu, u64 timestamp)
 {
        struct power_event *pwr = zalloc(sizeof(*pwr));
 
        pwr->end_time = timestamp;
        pwr->cpu = cpu;
        pwr->type = CSTATE;
-       pwr->next = power_events;
+       pwr->next = tchart->power_events;
 
-       power_events = pwr;
+       tchart->power_events = pwr;
 }
 
 static void p_state_change(struct timechart *tchart, int cpu, u64 timestamp, u64 new_freq)
        pwr->end_time = timestamp;
        pwr->cpu = cpu;
        pwr->type = PSTATE;
-       pwr->next = power_events;
+       pwr->next = tchart->power_events;
 
        if (!pwr->start_time)
                pwr->start_time = tchart->first_time;
 
-       power_events = pwr;
+       tchart->power_events = pwr;
 
        cpus_pstate_state[cpu] = new_freq;
        cpus_pstate_start_times[cpu] = timestamp;
        u32 cpu_id = perf_evsel__intval(evsel, sample, "cpu_id");
 
        if (state == (u32)PWR_EVENT_EXIT)
-               c_state_end(cpu_id, sample->time);
+               c_state_end(tchart, cpu_id, sample->time);
        else
                c_state_start(cpu_id, sample->time, state);
        return 0;
 }
 
 static int
-process_sample_power_end(struct timechart *tchart __maybe_unused,
+process_sample_power_end(struct timechart *tchart,
                         struct perf_evsel *evsel __maybe_unused,
                         struct perf_sample *sample,
                         const char *backtrace __maybe_unused)
 {
-       c_state_end(sample->cpu, sample->time);
+       c_state_end(tchart, sample->cpu, sample->time);
        return 0;
 }
 
                pwr->end_time = tchart->last_time;
                pwr->cpu = cpu;
                pwr->type = CSTATE;
-               pwr->next = power_events;
+               pwr->next = tchart->power_events;
 
-               power_events = pwr;
+               tchart->power_events = pwr;
 #endif
                /* P state */
 
                pwr->end_time = tchart->last_time;
                pwr->cpu = cpu;
                pwr->type = PSTATE;
-               pwr->next = power_events;
+               pwr->next = tchart->power_events;
 
                if (!pwr->start_time)
                        pwr->start_time = tchart->first_time;
                if (!pwr->state)
                        pwr->state = tchart->min_freq;
-               power_events = pwr;
+               tchart->power_events = pwr;
        }
 }
 
 static void draw_c_p_states(struct timechart *tchart)
 {
        struct power_event *pwr;
-       pwr = power_events;
+       pwr = tchart->power_events;
 
        /*
         * two pass drawing so that the P state bars are on top of the C state blocks
                pwr = pwr->next;
        }
 
-       pwr = power_events;
+       pwr = tchart->power_events;
        while (pwr) {
                if (pwr->type == PSTATE) {
                        if (!pwr->state)