[PATCH 41/63] perf trace: Allow suppressing the syscall argument names

Arnaldo Carvalho de Melo
2018-12-18T22:13:44Z

To show just the values:

Default:

# trace -e open*,close,*sleep sleep 1
openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC ) = 3
close(fd: 3 ) = 0
openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC ) = 3
close(fd: 3 ) = 0
openat(dfd: CWD, filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
close(fd: 3 ) = 0
nanosleep(rqtp: 0x7ffc0c4ea0d0, rmtp: 0 ) = 0
close(fd: 1 ) = 0
close(fd: 2 ) = 0
#

Remove it:

# perf config trace.show_arg_names=no
# trace -e open*,close,*sleep sleep 1
openat(CWD, /etc/ld.so.cache, CLOEXEC ) = 3
close(3 ) = 0
openat(CWD, /lib64/libc.so.6, CLOEXEC ) = 3
close(3 ) = 0
openat(CWD, /usr/lib/locale/locale-archive, CLOEXEC ) = 3
close(3 ) = 0
nanosleep(0x7ffced3a8c40, 0 ) = 0
close(1 ) = 0
close(2 ) = 0
#

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ta9tbdwgodpw719sr2bjm8eb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/Documentation/perf-config.txt | 4 ++++
tools/perf/builtin-trace.c | 22 ++++++++++++++++++----
2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index ecd1e9514925..35108fd61fa6 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -532,6 +532,10 @@ trace.*::
trace.no_inherit::
Do not follow children threads.

+ trace.show_arg_names::
+ Should syscall argument names be printed? If not then trace.show_zeros
+ will be set.
+
trace.show_duration::
Show syscall duration.

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index e978ce034863..95dfcb851604 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -130,6 +130,7 @@ struct trace {
bool show_tstamp;
bool show_duration;
bool show_zeros;
+ bool show_arg_names;
bool force;
bool vfs_getname;
int trace_pgfaults;
@@ -1613,8 +1614,11 @@ static size_t syscall__scnprintf_args(struct syscall *sc, char *bf, size_t size,
sc->arg_fmt[arg.idx].parm))
continue;

- printed += scnprintf(bf + printed, size - printed,
- "%s%s: ", printed ? ", " : "", field->name);
+ printed += scnprintf(bf + printed, size - printed, "%s", printed ? ", " : "");
+
+ if (trace->show_arg_names)
+ printed += scnprintf(bf + printed, size - printed, "%s: ", field->name);
+
printed += syscall__scnprintf_val(sc, bf + printed, size - printed, &arg, val);
}
} else if (IS_ERR(sc->tp_format)) {
@@ -3546,12 +3550,21 @@ static int trace__config(const char *var, const char *value, void *arg)
trace->show_tstamp = perf_config_bool(var, value);
} else if (!strcmp(var, "trace.show_duration")) {
trace->show_duration = perf_config_bool(var, value);
+ } else if (!strcmp(var, "trace.show_arg_names")) {
+ trace->show_arg_names = perf_config_bool(var, value);
+ if (!trace->show_arg_names)
+ trace->show_zeros = true;
} else if (!strcmp(var, "trace.show_zeros")) {
- trace->show_zeros = perf_config_bool(var, value);
+ bool new_show_zeros = perf_config_bool(var, value);
+ if (!trace->show_arg_names && !new_show_zeros) {
+ pr_warning("trace.show_zeros has to be set when trace.show_arg_names=no\n");
+ goto out;
+ }
+ trace->show_zeros = new_show_zeros;
} else if (!strcmp(var, "trace.no_inherit")) {
trace->opts.no_inherit = perf_config_bool(var, value);
}
-
+out:
return err;
}

@@ -3582,6 +3595,7 @@ int cmd_trace(int argc, const char **argv)
.show_comm = true,
.show_tstamp = true,
.show_duration = true,
+ .show_arg_names = true,
.trace_syscalls = false,
.kernel_syscallchains = false,
.max_stack = UINT_MAX,
--
2.19.2