[PATCH 6/8] perf thread-stack: Allocate an array of thread stacks

From: Adrian Hunter
Date: Fri Dec 21 2018 - 07:08:29 EST


In preparation for fixing thread stack processing for the idle task,
allocate an array of thread stacks.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
tools/perf/util/thread-stack.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
index 4340381d54c2..a896d89fe5f7 100644
--- a/tools/perf/util/thread-stack.c
+++ b/tools/perf/util/thread-stack.c
@@ -114,20 +114,26 @@ static int thread_stack__init(struct thread_stack *ts, struct thread *thread,
static struct thread_stack *thread_stack__new(struct thread *thread,
struct call_return_processor *crp)
{
- struct thread_stack *ts;
-
- ts = zalloc(sizeof(struct thread_stack));
- if (!ts)
- return NULL;
-
- ts->arr_sz = 1;
-
- if (thread_stack__init(ts, thread, crp)) {
- free(ts);
- return NULL;
+ struct thread_stack *ts = thread->ts, *new_ts;
+ unsigned int old_sz = ts ? ts->arr_sz : 0;
+ unsigned int new_sz = 1;
+
+ if (!ts || new_sz > old_sz) {
+ new_ts = calloc(new_sz, sizeof(*ts));
+ if (!new_ts)
+ return NULL;
+ if (ts)
+ memcpy(new_ts, ts, old_sz * sizeof(*ts));
+ new_ts->arr_sz = new_sz;
+ if (thread->ts)
+ zfree(&thread->ts);
+ thread->ts = new_ts;
+ ts = new_ts;
}

- thread->ts = ts;
+ if (!ts->stack &&
+ thread_stack__init(ts, thread, crp))
+ return NULL;

return ts;
}
--
2.17.1