diff options
Diffstat (limited to 'tools/perf/util/thread-stack.c')
| -rw-r--r-- | tools/perf/util/thread-stack.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c index cd8a948d03ec..747fdc237c9c 100644 --- a/tools/perf/util/thread-stack.c +++ b/tools/perf/util/thread-stack.c @@ -497,6 +497,63 @@ void thread_stack__sample(struct thread *thread, int cpu, chain->nr = i; } +/* + * Hardware sample records, created some time after the event occurred, need to + * have subsequent addresses removed from the call chain. + */ +void thread_stack__sample_late(struct thread *thread, int cpu, + struct ip_callchain *chain, size_t sz, + u64 sample_ip, u64 kernel_start) +{ + struct thread_stack *ts = thread__stack(thread, cpu); + u64 sample_context = callchain_context(sample_ip, kernel_start); + u64 last_context, context, ip; + size_t nr = 0, j; + + if (sz < 2) { + chain->nr = 0; + return; + } + + if (!ts) + goto out; + + /* + * When tracing kernel space, kernel addresses occur at the top of the + * call chain after the event occurred but before tracing stopped. + * Skip them. + */ + for (j = 1; j <= ts->cnt; j++) { + ip = ts->stack[ts->cnt - j].ret_addr; + context = callchain_context(ip, kernel_start); + if (context == PERF_CONTEXT_USER || + (context == sample_context && ip == sample_ip)) + break; + } + + last_context = sample_ip; /* Use sample_ip as an invalid context */ + + for (; nr < sz && j <= ts->cnt; nr++, j++) { + ip = ts->stack[ts->cnt - j].ret_addr; + context = callchain_context(ip, kernel_start); + if (context != last_context) { + if (nr >= sz - 1) + break; + chain->ips[nr++] = context; + last_context = context; + } + chain->ips[nr] = ip; + } +out: + if (nr) { + chain->nr = nr; + } else { + chain->ips[0] = sample_context; + chain->ips[1] = sample_ip; + chain->nr = 2; + } +} + struct call_return_processor * call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), void *data) |