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perf script: Allow adding and removing fields 

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 tid,cpu,time,event,sym,ip,dso,period | head -1
  swapper  0 [000] 504345.383126:          1 cycles:  ffffffff90060c66 native_write_msr ([kernel.kallsyms])

with the new syntax

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

The new syntax cannot be mixed with normal overriding.

v2: Fix example in description. Use tid vs pid. No functional changes.
v3: Don't skip initialization when user specified explicit type.
v4: Rebase. Remove empty line.

Committer testing:

  # perf record -a usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 1.748 MB perf.data (14 samples) ]

Without a explicit field list specified via -F, defaults to:

  # perf script | head -2
      perf 6338 [000] 18467.058607: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
   swapper    0 [001] 18467.058617: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
  #

Which is equivalent to:

  # perf script -F comm,tid,cpu,time,period,event,ip,sym,dso | head -2
      perf 6338 [000] 18467.058607: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
   swapper    0 [001] 18467.058617: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
  #

So if we want to remove the comm, as in your original example, we would have to
figure out the default field list and remove ' comm' from it:

  # perf script -F tid,cpu,time,period,event,ip,sym,dso | head -2
   6338 [000] 18467.058607: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
      0 [001] 18467.058617: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
  #

With your patch this becomes simpler, one can remove fields by prefixing them
with '-':

  # perf script -F -comm | head -2
  6338 [000] 18467.058607: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
     0 [001] 18467.058617: 1 cycles: ffffffff89060c36 native_write_msr (/lib/modules/4.11.0-rc8+/build/vmlinux)
  #

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Milian Wolff <milian.wolff@kdab.com>
Link: http://lkml.kernel.org/r/20170602154810.15875-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Andi Kleen 2017-06-02 08:48:10 -07:00 committed by Arnaldo Carvalho de Melo
parent 8c1cedb446
commit 36ce565114
2 changed files with 42 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
tools/perf/Documentation/perf-script.txt
View File

@ -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.:

37
tools/perf/builtin-script.c
View File

@ -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;
@ -1772,6 +1773,10 @@ 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 +1787,30 @@ 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 +1827,12 @@ 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) {
@ -1826,7 +1852,11 @@ 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;
@ -2444,6 +2474,7 @@ 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,"