Add sched_switch plugin to make the events look more like the old plugin

The event output for scheduler context switches and wakeups changed
the output format. This adds a plugin to make those changes look
more like the sched_switch plugin.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

2 files changed, 172 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 1b73a9e..f159a46 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,8 @@ LIBS = -L. -ltracecmd -ldl
 %.o: %.c
         $(CC) -c $(CFLAGS) $(EXT) $(INCLUDES) $< -o $@
 
-TARGETS = libparsevent.a libtracecmd.a trace-cmd plugin_hrtimer.so plugin_mac80211.so
+TARGETS = libparsevent.a libtracecmd.a trace-cmd plugin_hrtimer.so plugin_mac80211.so \
+        plugin_sched_switch.so
 
 all: $(TARGETS)
 
@@ -63,6 +64,12 @@ plugin_hrtimer.o: plugin_hrtimer.c parse-events.h
 plugin_hrtimer.so: plugin_hrtimer.o
         $(CC) -shared -nostartfiles -o $@ $<
 
+plugin_sched_switch.o: plugin_sched_switch.c parse-events.h
+        $(CC) -c $(CFLAGS) -fPIC -o $@ $<
+
+plugin_sched_switch.so: plugin_sched_switch.o
+        $(CC) -shared -nostartfiles -o $@ $<
+
 plugin_mac80211.o: plugin_mac80211.c parse-events.h
         $(CC) -c $(CFLAGS) -fPIC -o $@ $<
 
diff --git a/plugin_sched_switch.c b/plugin_sched_switch.c
new file mode 100644
index 0000000..b85a12a
--- /dev/null
+++ b/plugin_sched_switch.c
@@ -0,0 +1,164 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "trace-cmd.h"
+
+static int get_field_val(struct trace_seq *s, void *data,
+                         struct event *event, const char *name,
+                         unsigned long long *val, int fail)
+{
+        struct format_field *field;
+
+        field = pevent_find_any_field(event, name);
+        if (!field) {
+                if (fail)
+                        trace_seq_printf(s, "<CANT FIND FIELD %s>", name);
+                return -1;
+        }
+
+        if (pevent_read_number_field(field, data, val)) {
+                if (fail)
+                        trace_seq_printf(s, " %s=INVALID", name);
+                return -1;
+        }
+
+        return 0;
+}
+
+static void write_state(struct trace_seq *s, int val)
+{
+        const char states[] = "SDTtZXxW";
+        int found = 0;
+        int i;
+
+        for (i=0; i < (sizeof(states) - 1); i++) {
+                if (!(val & (1 << i)))
+                        continue;
+
+                if (found)
+                        trace_seq_putc(s, '|');
+
+                found = 1;
+                trace_seq_putc(s, states[i]);
+        }
+
+        if (!found)
+                trace_seq_putc(s, 'R');
+}
+
+static int sched_wakeup_handler(struct trace_seq *s, void *data, int size,
+                                struct event *event, int cpu,
+                                unsigned long long nsecs)
+{
+        struct format_field *field;
+        unsigned long long val;
+
+        if (get_field_val(s, data, event, "common_pid", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "prev_prio", &val, 0))
+                trace_seq_puts(s, "?:");
+        else
+                trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "prev_state", &val, 0))
+                trace_seq_putc(s, '?');
+        else
+                write_state(s, val);
+
+        trace_seq_puts(s, " +   ");
+
+        if (get_field_val(s, data, event, "pid", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "prio", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "state", &val, 0))
+                trace_seq_putc(s, '?');
+        else
+                write_state(s, val);
+
+        trace_seq_putc(s, ' ');
+
+        field = pevent_find_any_field(event, "comm");
+        if (!field) {
+                trace_seq_printf(s, "<CANT FIND FIELD %s>", "next_comm");
+                return trace_seq_putc(s, '!');
+        }
+
+        trace_seq_printf(s, "%.*s", field->size, (char *)(data + field->offset));
+
+        if (get_field_val(s, data, event, "success", &val, 0) == 0)
+                trace_seq_puts(s, val ? " Success" : " Failed");
+
+        return 0;
+}
+
+static int sched_switch_handler(struct trace_seq *s, void *data, int size,
+                                struct event *event, int cpu,
+                                unsigned long long nsecs)
+{
+        struct format_field *field;
+        unsigned long long val;
+
+        if (get_field_val(s, data, event, "prev_pid", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "prev_prio", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "prev_state", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        write_state(s, val);
+
+        trace_seq_puts(s, " ==> ");
+
+        if (get_field_val(s, data, event, "next_pid", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        if (get_field_val(s, data, event, "next_prio", &val, 1))
+                return trace_seq_putc(s, '!');
+
+        trace_seq_printf(s, "%lld:", val);
+
+        trace_seq_putc(s, ' ');
+
+        field = pevent_find_any_field(event, "next_comm");
+        if (!field) {
+                trace_seq_printf(s, "<CANT FIND FIELD %s>", "next_comm");
+                return trace_seq_putc(s, '!');
+        }
+
+        trace_seq_printf(s, "%.*s", field->size, (char *)(data + field->offset));
+
+        return 0;
+}
+
+int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
+{
+        pevent_register_event_handler(pevent, -1, "sched", "sched_switch",
+                                      sched_switch_handler);
+
+        pevent_register_event_handler(pevent, -1, "sched", "sched_wakeup",
+                                      sched_wakeup_handler);
+
+        pevent_register_event_handler(pevent, -1, "sched", "sched_wakeup_new",
+                                      sched_wakeup_handler);
+
+        return 0;
+}