1 files changed, 35 insertions, 9 deletions

diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
index c091635bf7dc..61a4286a74dc 100644
--- a/tools/perf/util/thread-stack.c
+++ b/tools/perf/util/thread-stack.c
@@ -310,20 +310,46 @@ void thread_stack__free(struct thread *thread)
         }
 }
 
+static inline u64 callchain_context(u64 ip, u64 kernel_start)
+{
+        return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL;
+}
+
 void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
-                          size_t sz, u64 ip)
+                          size_t sz, u64 ip, u64 kernel_start)
 {
-        size_t i;
+        u64 context = callchain_context(ip, kernel_start);
+        u64 last_context;
+        size_t i, j;
 
-        if (!thread || !thread->ts)
-                chain->nr = 1;
-        else
-                chain->nr = min(sz, thread->ts->cnt + 1);
+        if (sz < 2) {
+                chain->nr = 0;
+                return;
+        }
 
-        chain->ips[0] = ip;
+        chain->ips[0] = context;
+        chain->ips[1] = ip;
+
+        if (!thread || !thread->ts) {
+                chain->nr = 2;
+                return;
+        }
+
+        last_context = context;
+
+        for (i = 2, j = 1; i < sz && j <= thread->ts->cnt; i++, j++) {
+                ip = thread->ts->stack[thread->ts->cnt - j].ret_addr;
+                context = callchain_context(ip, kernel_start);
+                if (context != last_context) {
+                        if (i >= sz - 1)
+                                break;
+                        chain->ips[i++] = context;
+                        last_context = context;
+                }
+                chain->ips[i] = ip;
+        }
 
-        for (i = 1; i < chain->nr; i++)
-                chain->ips[i] = thread->ts->stack[thread->ts->cnt - i].ret_addr;
+        chain->nr = i;
 }
 
 struct call_return_processor *