[PATCH 4/8] perf thread-stack: Allow for a thread stack array

From: Adrian Hunter
Date: Fri Dec 21 2018 - 07:08:15 EST


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

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/thread-stack.c | 40 +++++++++++++++++++++++++++++-----
1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
index e13127755293..e59f6fa4c67d 100644
--- 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;
}

--
2.17.1