1 files changed, 73 insertions, 10 deletions

diff --git a/trace-plot-cpu.c b/trace-plot-cpu.c
index 1c86df8..0e7f5e8 100644
--- a/trace-plot-cpu.c
+++ b/trace-plot-cpu.c
@@ -27,6 +27,7 @@ struct cpu_plot_info {
         int                     cpu;
         unsigned long long      last_time;
         int                     last_pid;
+        struct record           *last_record;
 };
 
 static gint hash_pid(gint val)
@@ -45,15 +46,10 @@ static void convert_nano(unsigned long long time, unsigned long *sec,
         *usec = (time / 1000) % 1000000;
 }
 
-static int cpu_plot_match_time(struct graph_info *ginfo, struct graph_plot *plot,
-                               unsigned long long time)
+static struct record *get_record_from_time(struct graph_info *ginfo, int cpu,
+                                           unsigned long long time)
 {
-        struct cpu_plot_info *cpu_info = plot->private;
         struct record *record;
-        long cpu;
-        int ret = 0;
-
-        cpu = cpu_info->cpu;
 
         tracecmd_set_cpu_to_timestamp(ginfo->handle, cpu, time);
         record = tracecmd_read_data(ginfo->handle, cpu);
@@ -61,6 +57,18 @@ static int cpu_plot_match_time(struct graph_info *ginfo, struct graph_plot *plot
                 free_record(record);
                 record = tracecmd_read_data(ginfo->handle, cpu);
         }
+
+        return record;
+}
+
+static int cpu_plot_match_time(struct graph_info *ginfo, struct graph_plot *plot,
+                               unsigned long long time)
+{
+        struct cpu_plot_info *cpu_info = plot->private;
+        struct record *record;
+        int ret = 0;
+
+        record = get_record_from_time(ginfo, cpu_info->cpu, time);
         if (record && record->ts == time)
                 ret = 1;
         free_record(record);
@@ -192,6 +200,41 @@ static void cpu_plot_start(struct graph_info *ginfo, struct graph_plot *plot,
         cpu = cpu_info->cpu;
         cpu_info->last_time = 0ULL;
         cpu_info->last_pid = -1;
+        cpu_info->last_record = NULL;
+}
+
+static void update_last_record(struct graph_info *ginfo,
+                               struct cpu_plot_info *cpu_info,
+                               struct record *record)
+{
+        struct tracecmd_input *handle = ginfo->handle;
+        struct record *trecord;
+        int filter;
+        int sched_pid;
+        int orig_pid;
+        int is_sched_switch;
+
+        if (record)
+                tracecmd_record_ref(record);
+        else
+                record = get_record_from_time(ginfo, cpu_info->cpu,
+                                              ginfo->view_end_time);
+
+        trecord = tracecmd_read_prev(handle, record);
+        free_record(record);
+
+        if (!trecord)
+                return;
+
+        filter = filter_record(ginfo, trecord,
+                               &orig_pid, &sched_pid,
+                               &is_sched_switch);
+        cpu_info->last_pid = is_sched_switch ? sched_pid : orig_pid;
+        cpu_info->last_record = trecord;
+        cpu_info->last_time = trecord->ts;
+        /* We moved the cursor, put it back */
+        trecord = tracecmd_read_data(handle, cpu_info->cpu);
+        free_record(trecord);
 }
 
 static int cpu_plot_event(struct graph_info *ginfo,
@@ -212,6 +255,9 @@ static int cpu_plot_event(struct graph_info *ginfo,
         cpu = cpu_info->cpu;
 
         if (!record) {
+                if (!cpu_info->last_record)
+                        update_last_record(ginfo, cpu_info, record);
+
                 /* Finish a box if the last record was not idle */
                 if (cpu_info->last_pid > 0) {
                         info->box = TRUE;
@@ -219,9 +265,24 @@ static int cpu_plot_event(struct graph_info *ginfo,
                         info->bend = ginfo->view_end_time;
                         info->bcolor = hash_pid(cpu_info->last_pid);
                 }
+                if (cpu_info->last_record) {
+                        free_record(cpu_info->last_record);
+                        cpu_info->last_record = NULL;
+                }
                 return 0;
         }
 
+        /*
+         * If last record is NULL, then it may exist off the
+         * viewable range. Search to see if one exists.
+         */
+        if (!cpu_info->last_record)
+                update_last_record(ginfo, cpu_info, record);
+
+        free_record(cpu_info->last_record);
+        cpu_info->last_record = record;
+        tracecmd_record_ref(record);
+
         cpu = cpu_info->cpu;
 
         filter = filter_record(ginfo, record, &orig_pid, &sched_pid, &is_sched_switch);
@@ -237,10 +298,12 @@ static int cpu_plot_event(struct graph_info *ginfo,
                                 cpu_info->last_pid = orig_pid;
                         else
                                 cpu_info->last_pid = pid;
-                }
 
-                /* Box should always use the original pid (prev in sched_switch) */
-                box_filter = trace_graph_filter_on_task(ginfo, orig_pid);
+                        /* Box should always use the original pid (prev in sched_switch) */
+                        box_filter = trace_graph_filter_on_task(ginfo, orig_pid);
+                } else
+                        box_filter = trace_graph_filter_on_task(ginfo, cpu_info->last_pid);
+
 
                 if (!box_filter && cpu_info->last_pid) {
                         info->bcolor = hash_pid(cpu_info->last_pid);