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Commit 36ce5651 authored by Andi Kleen's avatar Andi Kleen Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: default avatarMilian Wolff <milian.wolff@kdab.com>
Link: http://lkml.kernel.org/r/20170602154810.15875-1-andi@firstfloor.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8c1cedb4

tools/perf/Documentation/perf-script.txt

+8 −0
Original line number Diff line number Diff line
@@ -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.:

tools/perf/builtin-script.c

+34 −3
Original line number Diff line number Diff line
@@ -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) {
@@ -1805,9 +1827,13 @@ 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

				} 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) {

				fprintf(stderr, "\'%s\' not valid for %s events.\n",
@@ -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,"