ftrace: add wakeup events to sched tracer

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

5 files changed, 88 insertions, 5 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f5898051fdd9..192c1354a7e0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -57,7 +57,7 @@ static struct trace_array	max_tr;
 static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
 
 static int                      tracer_enabled = 1;
-static unsigned long            trace_nr_entries = 16384UL;
+static unsigned long            trace_nr_entries = 65536UL;
 
 static struct tracer            *trace_types __read_mostly;
 static struct tracer            *current_trace __read_mostly;
@@ -87,6 +87,7 @@ enum trace_type {
 
         TRACE_FN,
         TRACE_CTX,
+        TRACE_WAKE,
         TRACE_SPECIAL,
 
         __TRACE_LAST_TYPE
@@ -711,6 +712,30 @@ tracing_sched_switch_trace(struct trace_array *tr,
                 wake_up (&trace_wait);
 }
 
+void
+tracing_sched_wakeup_trace(struct trace_array *tr,
+                           struct trace_array_cpu *data,
+                           struct task_struct *wakee, struct task_struct *curr,
+                           unsigned long flags)
+{
+        struct trace_entry *entry;
+        unsigned long irq_flags;
+
+        spin_lock_irqsave(&data->lock, irq_flags);
+        entry                   = tracing_get_trace_entry(tr, data);
+        tracing_generic_entry_update(entry, flags);
+        entry->type             = TRACE_WAKE;
+        entry->ctx.prev_pid     = curr->pid;
+        entry->ctx.prev_prio    = curr->prio;
+        entry->ctx.prev_state   = curr->state;
+        entry->ctx.next_pid     = wakee->pid;
+        entry->ctx.next_prio    = wakee->prio;
+        spin_unlock_irqrestore(&data->lock, irq_flags);
+
+        if (!(trace_flags & TRACE_ITER_BLOCK))
+                wake_up(&trace_wait);
+}
+
 #ifdef CONFIG_FTRACE
 static void
 function_trace_call(unsigned long ip, unsigned long parent_ip)
@@ -1183,13 +1208,14 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
                 trace_seq_puts(s, ")\n");
                 break;
         case TRACE_CTX:
+        case TRACE_WAKE:
                 S = entry->ctx.prev_state < sizeof(state_to_char) ?
                         state_to_char[entry->ctx.prev_state] : 'X';
                 comm = trace_find_cmdline(entry->ctx.next_pid);
-                trace_seq_printf(s, " %d:%d:%c --> %d:%d %s\n",
+                trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d %s\n",
                                  entry->ctx.prev_pid,
                                  entry->ctx.prev_prio,
-                                 S,
+                                 S, entry->type == TRACE_CTX ? "==>" : "  +",
                                  entry->ctx.next_pid,
                                  entry->ctx.next_prio,
                                  comm);
@@ -1256,12 +1282,14 @@ static int print_trace_fmt(struct trace_iterator *iter)
                         return 0;
                 break;
         case TRACE_CTX:
+        case TRACE_WAKE:
                 S = entry->ctx.prev_state < sizeof(state_to_char) ?
                         state_to_char[entry->ctx.prev_state] : 'X';
-                ret = trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n",
+                ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d\n",
                                        entry->ctx.prev_pid,
                                        entry->ctx.prev_prio,
                                        S,
+                                       entry->type == TRACE_CTX ? "==>" : "  +",
                                        entry->ctx.next_pid,
                                        entry->ctx.next_prio);
                 if (!ret)
@@ -1301,8 +1329,11 @@ static int print_raw_fmt(struct trace_iterator *iter)
                         return 0;
                 break;
         case TRACE_CTX:
+        case TRACE_WAKE:
                 S = entry->ctx.prev_state < sizeof(state_to_char) ?
                         state_to_char[entry->ctx.prev_state] : 'X';
+                if (entry->type == TRACE_WAKE)
+                        S = '+';
                 ret = trace_seq_printf(s, "%d %d %c %d %d\n",
                                        entry->ctx.prev_pid,
                                        entry->ctx.prev_prio,
@@ -1355,8 +1386,11 @@ static int print_hex_fmt(struct trace_iterator *iter)
                 SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
                 break;
         case TRACE_CTX:
+        case TRACE_WAKE:
                 S = entry->ctx.prev_state < sizeof(state_to_char) ?
                         state_to_char[entry->ctx.prev_state] : 'X';
+                if (entry->type == TRACE_WAKE)
+                        S = '+';
                 SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
                 SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
                 SEQ_PUT_HEX_FIELD_RET(s, S);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2b7352bf1ce6..90e0ba0f6eba 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -164,6 +164,12 @@ void tracing_sched_switch_trace(struct trace_array *tr,
                                 struct task_struct *next,
                                 unsigned long flags);
 void tracing_record_cmdline(struct task_struct *tsk);
+
+void tracing_sched_wakeup_trace(struct trace_array *tr,
+                                struct trace_array_cpu *data,
+                                struct task_struct *wakee,
+                                struct task_struct *cur,
+                                unsigned long flags);
 void trace_special(struct trace_array *tr,
                    struct trace_array_cpu *data,
                    unsigned long arg1,
@@ -194,11 +200,17 @@ extern cycle_t ftrace_now(int cpu);
 #ifdef CONFIG_SCHED_TRACER
 extern void
 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next);
+extern void
+wakeup_sched_wakeup(struct task_struct *wakee, struct task_struct *curr);
 #else
 static inline void
 wakeup_sched_switch(struct task_struct *prev, struct task_struct *next)
 {
 }
+static inline void
+wakeup_sched_wakeup(struct task_struct *wakee, struct task_struct *curr)
+{
+}
 #endif
 
 #ifdef CONFIG_CONTEXT_SWITCH_TRACER
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index b738eaca1dbe..8b1cf1a3aee0 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -41,6 +41,29 @@ ctx_switch_func(struct task_struct *prev, struct task_struct *next)
         local_irq_restore(flags);
 }
 
+static void wakeup_func(struct task_struct *wakee, struct task_struct *curr)
+{
+        struct trace_array *tr = ctx_trace;
+        struct trace_array_cpu *data;
+        unsigned long flags;
+        long disabled;
+        int cpu;
+
+        if (!tracer_enabled)
+                return;
+
+        local_irq_save(flags);
+        cpu = raw_smp_processor_id();
+        data = tr->data[cpu];
+        disabled = atomic_inc_return(&data->disabled);
+
+        if (likely(disabled == 1))
+                tracing_sched_wakeup_trace(tr, data, wakee, curr, flags);
+
+        atomic_dec(&data->disabled);
+        local_irq_restore(flags);
+}
+
 void ftrace_ctx_switch(struct task_struct *prev, struct task_struct *next)
 {
         tracing_record_cmdline(prev);
@@ -57,6 +80,19 @@ void ftrace_ctx_switch(struct task_struct *prev, struct task_struct *next)
         wakeup_sched_switch(prev, next);
 }
 
+void
+ftrace_wake_up_task(struct task_struct *wakee, struct task_struct *curr)
+{
+        tracing_record_cmdline(curr);
+
+        wakeup_func(wakee, curr);
+
+        /*
+         * Chain to the wakeup tracer (this is a NOP if disabled):
+         */
+        wakeup_sched_wakeup(wakee, curr);
+}
+
 static void sched_switch_reset(struct trace_array *tr)
 {
         int cpu;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 662679c78b66..87fa7b253b57 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -202,7 +202,7 @@ out:
 }
 
 void
-ftrace_wake_up_task(struct task_struct *wakee, struct task_struct *curr)
+wakeup_sched_wakeup(struct task_struct *wakee, struct task_struct *curr)
 {
         if (likely(!tracer_enabled))
                 return;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 85715b86a342..39dd452647da 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -8,6 +8,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
         switch (entry->type) {
         case TRACE_FN:
         case TRACE_CTX:
+        case TRACE_WAKE:
                 return 1;
         }
         return 0;