Commit 7f94af7a authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
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perf tools: Introduce 'P' modifier to request max precision 



The 'P' will cause the event to get maximum possible detected precise
level.

Following record:
  $ perf record -e cycles:P ...

will detect maximum precise level for 'cycles' event and use it.

Commiter note:

Testing it:

  $ perf record -e cycles:P usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (9 samples) ]
  $ perf evlist
  cycles:P
  $ perf evlist -v
  cycles:P: size: 112, { sample_period, sample_freq }: 4000, sample_type:
  IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1,
  enable_on_exec: 1, task: 1, precise_ip: 2, sample_id_all: 1, mmap2: 1,
  comm_exec: 1
  $

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1444068369-20978-6-git-send-email-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 45cf6c33

tools/perf/Documentation/perf-list.txt

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ counted. The following modifiers exist: 
 G - guest counting (in KVM guests)

 H - host counting (not in KVM guests)

 p - precise level

 P - use maximum detected precise level

 S - read sample value (PERF_SAMPLE_READ)

 D - pin the event to the PMU

tools/perf/util/evsel.c

+3 −0
Original line number Diff line number Diff line
@@ -882,6 +882,9 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts) 
		attr->clockid = opts->clockid;

	}



	if (evsel->precise_max)

		perf_event_attr__set_max_precise_ip(attr);



	/*

	 * Apply event specific term settings,

	 * it overloads any global configuration.

tools/perf/util/evsel.h

+1 −0
Original line number Diff line number Diff line
@@ -111,6 +111,7 @@ struct perf_evsel { 
	bool			system_wide;

	bool			tracking;

	bool			per_pkg;

	bool			precise_max;

	/* parse modifier helper */

	int			exclude_GH;

	int			nr_members;

tools/perf/util/parse-events.c

+7 −1
Original line number Diff line number Diff line
@@ -923,6 +923,7 @@ struct event_modifier { 
	int eG;

	int eI;

	int precise;

	int precise_max;

	int exclude_GH;

	int sample_read;

	int pinned;
@@ -938,6 +939,7 @@ static int get_event_modifier(struct event_modifier *mod, char *str, 
	int eG = evsel ? evsel->attr.exclude_guest : 0;

	int eI = evsel ? evsel->attr.exclude_idle : 0;

	int precise = evsel ? evsel->attr.precise_ip : 0;

	int precise_max = 0;

	int sample_read = 0;

	int pinned = evsel ? evsel->attr.pinned : 0;
@@ -974,6 +976,8 @@ static int get_event_modifier(struct event_modifier *mod, char *str, 
			/* use of precise requires exclude_guest */

			if (!exclude_GH)

				eG = 1;

		} else if (*str == 'P') {

			precise_max = 1;

		} else if (*str == 'S') {

			sample_read = 1;

		} else if (*str == 'D') {
@@ -1004,6 +1008,7 @@ static int get_event_modifier(struct event_modifier *mod, char *str, 
	mod->eG = eG;

	mod->eI = eI;

	mod->precise = precise;

	mod->precise_max = precise_max;

	mod->exclude_GH = exclude_GH;

	mod->sample_read = sample_read;

	mod->pinned = pinned;
@@ -1020,7 +1025,7 @@ static int check_modifier(char *str) 
	char *p = str;



	/* The sizeof includes 0 byte as well. */

	if (strlen(str) > (sizeof("ukhGHpppSDI") - 1))

	if (strlen(str) > (sizeof("ukhGHpppPSDI") - 1))

		return -1;



	while (*p) {
@@ -1059,6 +1064,7 @@ int parse_events__modifier_event(struct list_head *list, char *str, bool add) 
		evsel->attr.exclude_idle   = mod.eI;

		evsel->exclude_GH          = mod.exclude_GH;

		evsel->sample_read         = mod.sample_read;

		evsel->precise_max         = mod.precise_max;



		if (perf_evsel__is_group_leader(evsel))

			evsel->attr.pinned = mod.pinned;

tools/perf/util/parse-events.l

+1 −1
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ num_raw_hex [a-fA-F0-9]+ 
name		[a-zA-Z_*?][a-zA-Z0-9_*?.]*

name_minus	[a-zA-Z_*?][a-zA-Z0-9\-_*?.]*

/* If you add a modifier you need to update check_modifier() */

modifier_event	[ukhpGHSDI]+

modifier_event	[ukhpPGHSDI]+

modifier_bp	[rwx]{1,3}



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