perf trace: Setup DWARF callchains for non-syscall events when --max-stack is used

Commit-ID:  75d501171462d8624fd14a2baa474476d6745e95
Gitweb:     https://git.kernel.org/tip/75d501171462d8624fd14a2baa474476d6745e95
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Mon, 15 Jan 2018 10:39:55 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Wed, 17 Jan 2018 10:23:32 -0300

perf trace: Setup DWARF callchains for non-syscall events when --max-stack is used

If we use:

	perf trace --max-stack=4

then the syscall events will use DWARF callchains, when available (libunwind enabled in the build) and the printing will stop at 4 levels.

When we introduced support for tracepoint events this ended up not applying for them, fix it.

Before:

  # perf trace --call-graph=dwarf --no-syscalls -e probe_libc:inet_pton ping -6 -c 1 ::1
  PING ::1(::1) 56 data bytes
  64 bytes from ::1: icmp_seq=1 ttl=64 time=0.058 ms

--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.058/0.058/0.058/0.000 ms

       0.000 probe_libc:inet_pton:(7fc6c2a16350))

#

After:

  # perf trace --call-graph=dwarf --no-syscalls -e probe_libc:inet_pton ping -6 -c 1 ::1
  PING ::1(::1) 56 data bytes
  64 bytes from ::1: icmp_seq=1 ttl=64 time=0.087 ms

--- ::1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.087/0.087/0.087/0.000 ms

       0.000 probe_libc:inet_pton:(7fbf9a041350))
                                         __inet_pton (inlined)
                                         gaih_inet.constprop.7 (/usr/lib64/libc-2.26.so)
                                         __GI_getaddrinfo (inlined)
                                         [0xffffaa947cb67f3f] (/usr/bin/ping)
                                         __libc_start_main (/usr/lib64/libc-2.26.so)
                                         [0xffffaa947cb68379] (/usr/bin/ping)

#

---
 tools/perf/builtin-trace.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

index 0362974..ee85c29 100644
@@ -2350,7 +2350,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 		goto out_delete_evlist;
 	}
 
-	perf_evlist__config(evlist, &trace->opts, NULL);
+	perf_evlist__config(evlist, &trace->opts, &callchain_param);
 
 	signal(SIGCHLD, sig_handler);
 	signal(SIGINT, sig_handler);

@@ -3065,8 +3065,9 @@ int cmd_trace(int argc, const char **argv)
 	}
 
 #ifdef HAVE_DWARF_UNWIND_SUPPORT
-	if ((trace.min_stack || max_stack_user_set) && !callchain_param.enabled && trace.trace_syscalls)
+	if ((trace.min_stack || max_stack_user_set) && !callchain_param.enabled) {
 		record_opts__parse_callchain(&trace.opts, &callchain_param, "dwarf", false);
+	}
 #endif
 
 	if (callchain_param.enabled) {