perf thread-stack: Allow for a thread stack array

In preparation for fixing thread stack processing for the idle task,
allow for a thread stack array.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20181221120620.9659-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
index d93cd286b04819b7ce0dff0e8001db3ff1a9f594..a5f7b9d8fc2385377e1bdb3b5d336cc06bbd3df9 100644 (file)
--- a/tools/perf/util/thread-stack.c
+++ b/tools/perf/util/thread-stack.c
@@ -60,6 +60,7 @@ struct thread_stack_entry {
  * @last_time: last timestamp
  * @crp: call/return processor
  * @comm: current comm
+ * @arr_sz: size of array if this is the first element of an array
  */
 struct thread_stack {
        struct thread_stack_entry *stack;
@@ -71,6 +72,7 @@ struct thread_stack {
        u64 last_time;
        struct call_return_processor *crp;
        struct comm *comm;
+       unsigned int arr_sz;
 };
 
 static int thread_stack__grow(struct thread_stack *ts)
@@ -100,6 +102,8 @@ static struct thread_stack *thread_stack__new(struct thread *thread,
        if (!ts)
                return NULL;
 
+       ts->arr_sz = 1;
+
        if (thread_stack__grow(ts)) {
                free(ts);
                return NULL;
@@ -234,11 +238,19 @@ static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts)
 int thread_stack__flush(struct thread *thread)
 {
        struct thread_stack *ts = thread->ts;
+       unsigned int pos;
+       int err = 0;
 
-       if (ts)
-               return __thread_stack__flush(thread, ts);
+       if (ts) {
+               for (pos = 0; pos < ts->arr_sz; pos++) {
+                       int ret = __thread_stack__flush(thread, ts + pos);
 
-       return 0;
+                       if (ret)
+                               err = ret;
+               }
+       }
+
+       return err;
 }
 
 int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
@@ -314,13 +326,29 @@ void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr)
        }
 }
 
+static void __thread_stack__free(struct thread *thread, struct thread_stack *ts)
+{
+       __thread_stack__flush(thread, ts);
+       zfree(&ts->stack);
+}
+
+static void thread_stack__reset(struct thread *thread, struct thread_stack *ts)
+{
+       unsigned int arr_sz = ts->arr_sz;
+
+       __thread_stack__free(thread, ts);
+       memset(ts, 0, sizeof(*ts));
+       ts->arr_sz = arr_sz;
+}
+
 void thread_stack__free(struct thread *thread)
 {
        struct thread_stack *ts = thread->ts;
+       unsigned int pos;
 
        if (ts) {
-               __thread_stack__flush(thread, ts);
-               zfree(&ts->stack);
+               for (pos = 0; pos < ts->arr_sz; pos++)
+                       __thread_stack__free(thread, ts + pos);
                zfree(&thread->ts);
        }
 }
@@ -611,7 +639,7 @@ int thread_stack__process(struct thread *thread, struct comm *comm,
 
        if (ts && !ts->crp) {
                /* Supersede thread_stack__event() */
-               thread_stack__free(thread);
+               thread_stack__reset(thread, ts);
                ts = NULL;
        }