[PATCH] perf, tools, script: Allow adding and removing fields

Andi Kleen
2017-05-01T19:47:53Z

From: Andi Kleen <ak@linux.intel.com>

With perf script it is common that we just want to add or remove a field.
Currently this requires figuring out the long list of default fields and
specifying them first, and then adding/removing the new field.

This patch adds a new + - syntax to merely add or remove fields,
that allows more succint and clearer command lines

For example to remove the comm field from PMU samples:

Previously

perf script -F pid,cpu,time,event,sym,ip,dso,period
0 [000] 504345.383126: 1 cycles: ffffffff90060c66 native_write_msr ([kernel.kallsyms])

with the new syntax

perf script -F -comm
0 [000] 504345.383126: 1 cycles: ffffffff90060c66 native_write_msr ([kernel.kallsyms])

The new syntax cannot be mixed with normal overriding.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
tools/perf/Documentation/perf-script.txt | 8 ++++++
tools/perf/builtin-script.c | 42 +++++++++++++++++++++++++++++---
2 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index cb0eda3925e6..4547120c6ad3 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -130,6 +130,14 @@ OPTIONS
i.e., the specified fields apply to all event types if the type string
is not given.

+ In addition to overriding fields, it is also possible to add or remove
+ fields from the defaults. For example
+
+ -F -cpu,+insn
+
+ removes the cpu field and adds the insn field. Adding/removing fields
+ cannot be mixed with normal overriding.
+
The arguments are processed in the order received. A later usage can
reset a prior request. e.g.:

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index d05aec491cff..f2970b118cd2 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1727,6 +1727,7 @@ static int parse_output_fields(const struct option *opt __maybe_unused,
int rc = 0;
char *str = strdup(arg);
int type = -1;
+ enum { DEFAULT, SET, ADD, REMOVE } change = DEFAULT;

if (!str)
return -ENOMEM;
@@ -1755,6 +1756,10 @@ static int parse_output_fields(const struct option *opt __maybe_unused,
goto out;
}

+ /* Don't override defaults for +- */
+ if (strchr(str, '+') || strchr(str, '-'))
+ goto parse;
+
if (output[type].user_set)
pr_warning("Overriding previous field request for %s events.\n",
event_type(type));
@@ -1772,6 +1777,10 @@ static int parse_output_fields(const struct option *opt __maybe_unused,
goto out;
}

+ /* Don't override defaults for +- */
+ if (strchr(str, '+') || strchr(str, '-'))
+ goto parse;
+
if (output_set_by_user())
pr_warning("Overriding previous field request for all events.\n");

@@ -1782,13 +1791,30 @@ static int parse_output_fields(const struct option *opt __maybe_unused,
}
}

+parse:
for (tok = strtok_r(tok, ",", &strtok_saveptr); tok; tok = strtok_r(NULL, ",", &strtok_saveptr)) {
+ if (*tok == '+') {
+ if (change == SET)
+ goto out_badmix;
+ change = ADD;
+ tok++;
+ } else if (*tok == '-') {
+ if (change == SET)
+ goto out_badmix;
+ change = REMOVE;
+ tok++;
+ } else {
+ if (change != SET && change != DEFAULT)
+ goto out_badmix;
+ change = SET;
+ }
+
for (i = 0; i < imax; ++i) {
if (strcmp(tok, all_output_options[i].str) == 0)
break;
}
if (i == imax && strcmp(tok, "flags") == 0) {
- print_flags = true;
+ print_flags = change == REMOVE ? false : true;
continue;
}
if (i == imax) {
@@ -1805,8 +1831,12 @@ static int parse_output_fields(const struct option *opt __maybe_unused,
if (output[j].invalid_fields & all_output_options[i].field) {
pr_warning("\'%s\' not valid for %s events. Ignoring.\n",
all_output_options[i].str, event_type(j));
- } else
- output[j].fields |= all_output_options[i].field;
+ } else {
+ if (change == REMOVE)
+ output[j].fields &= ~all_output_options[i].field;
+ else
+ output[j].fields |= all_output_options[i].field;
+ }
}
} else {
if (output[type].invalid_fields & all_output_options[i].field) {
@@ -1826,10 +1856,15 @@ static int parse_output_fields(const struct option *opt __maybe_unused,
"Events will not be displayed.\n", event_type(type));
}
}
+ goto out;

+out_badmix:
+ fprintf(stderr, "Cannot mix +-field with overridden fields\n");
+ rc = -EINVAL;
out:
free(str);
return rc;
+
}

/* Helper function for filesystems that return a dent->d_type DT_UNKNOWN */
@@ -2444,6 +2479,7 @@ int cmd_script(int argc, const char **argv)
symbol__config_symfs),
OPT_CALLBACK('F', "fields", NULL, "str",
"comma separated output fields prepend with 'type:'. "
+ "+field to add and -field to remove."
"Valid types: hw,sw,trace,raw. "
"Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,"
"addr,symoff,period,iregs,brstack,brstacksym,flags,"
--
2.9.3