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Message-Id: <1460426030-27319-11-git-send-email-acme@kernel.org>
Date: Mon, 11 Apr 2016 22:53:41 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Ingo Molnar <mingo@...nel.org>
Cc: linux-kernel@...r.kernel.org, Milian Wolff <milian.wolff@...b.com>,
Adrian Hunter <adrian.hunter@...el.com>,
David Ahern <dsahern@...il.com>, Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>,
Wang Nan <wangnan0@...wei.com>,
Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 10/19] perf trace: Add support for printing call chains on sys_exit events.
From: Milian Wolff <milian.wolff@...b.com>
Now, one can print the call chain for every encountered sys_exit event,
e.g.:
$ perf trace -e nanosleep --call-graph dwarf path/to/ex_sleep
1005.757 (1000.090 ms): ex_sleep/13167 nanosleep(...) = 0
syscall_slow_exit_work ([kernel.kallsyms])
syscall_return_slowpath ([kernel.kallsyms])
int_ret_from_sys_call ([kernel.kallsyms])
__nanosleep (/usr/lib/libc-2.23.so)
[unknown] (/usr/lib/libQt5Core.so.5.6.0)
QThread::sleep (/usr/lib/libQt5Core.so.5.6.0)
main (path/to/ex_sleep)
__libc_start_main (/usr/lib/libc-2.23.so)
_start (path/to/ex_sleep)
Note that it is advised to increase the number of mmap pages to prevent
event losses when using this new feature. Often, adding `-m 10M` to the
`perf trace` invocation is enough.
This feature is also available in strace when built with libunwind via
`strace -k`. Performance wise, this solution is much better:
$ time find path/to/linux &> /dev/null
real 0m0.051s
user 0m0.013s
sys 0m0.037s
$ time perf trace -m 800M --call-graph dwarf find path/to/linux &> /dev/null
real 0m2.624s
user 0m1.203s
sys 0m1.333s
$ time strace -k find path/to/linux &> /dev/null
real 0m35.398s
user 0m10.403s
sys 0m23.173s
Note that it is currently not possible to configure the print output.
Adding such a feature, similar to what is available in `perf script` via
its `--fields` knob can be added later on.
Signed-off-by: Milian Wolff <milian.wolff@...b.com>
Tested-by: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Adrian Hunter <adrian.hunter@...el.com>
Cc: David Ahern <dsahern@...il.com>
Cc: Jiri Olsa <jolsa@...nel.org>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Wang Nan <wangnan0@...wei.com>
LPU-Reference: 1460115255-17648-1-git-send-email-milian.wolff@...b.com
[ Split from a larger patch, do not print the IP, left align,
remove dup call symbol__init(), added man page entry ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
tools/perf/Documentation/perf-trace.txt | 6 ++++++
tools/perf/builtin-trace.c | 22 ++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index 13293de8869f..ed485df16409 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -117,6 +117,12 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
--syscalls::
Trace system calls. This options is enabled by default.
+--call-graph [mode,type,min[,limit],order[,key][,branch]]::
+ Setup and enable call-graph (stack chain/backtrace) recording.
+ See `--call-graph` section in perf-record and perf-report
+ man pages for details. The ones that are most useful in 'perf trace'
+ are 'dwarf' and 'lbr', where available, try: 'perf trace --call-graph dwarf'.
+
--event::
Trace other events, see 'perf list' for a complete list.
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 27d987030627..8c587a8d3742 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -34,6 +34,7 @@
#include "trace-event.h"
#include "util/parse-events.h"
#include "util/bpf-loader.h"
+#include "callchain.h"
#include "syscalltbl.h"
#include <libaudit.h> /* FIXME: Still needed for audit_errno_to_name */
@@ -2190,6 +2191,21 @@ signed_print:
goto signed_print;
fputc('\n', trace->output);
+
+ if (sample->callchain) {
+ struct addr_location al;
+ /* TODO: user-configurable print_opts */
+ const unsigned int print_opts = PRINT_IP_OPT_SYM
+ | PRINT_IP_OPT_DSO;
+
+ if (machine__resolve(trace->host, &al, sample) < 0) {
+ pr_err("problem processing %d event, skipping it.\n",
+ event->header.type);
+ goto out_put;
+ }
+ perf_evsel__print_ip(evsel, sample, &al, 38, print_opts,
+ scripting_max_stack, trace->output);
+ }
out:
ttrace->entry_pending = false;
err = 0;
@@ -3250,6 +3266,9 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
"Trace pagefaults", parse_pagefaults, "maj"),
OPT_BOOLEAN(0, "syscalls", &trace.trace_syscalls, "Trace syscalls"),
OPT_BOOLEAN('f', "force", &trace.force, "don't complain, do it"),
+ OPT_CALLBACK(0, "call-graph", &trace.opts,
+ "record_mode[,record_size]", record_callchain_help,
+ &record_parse_callchain_opt),
OPT_UINTEGER(0, "proc-map-timeout", &trace.opts.proc_map_timeout,
"per thread proc mmap processing timeout in ms"),
OPT_END()
@@ -3285,6 +3304,9 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
trace.opts.sample_time = true;
}
+ if (trace.opts.callgraph_set)
+ symbol_conf.use_callchain = true;
+
if (trace.evlist->nr_entries > 0)
evlist__set_evsel_handler(trace.evlist, trace__event_handler);
--
2.5.5
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