Commit 6282a1f4 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf lock: Add -E/--entries option 



Like in 'perf top', the -E option can limit number of entries to print.

It can be useful when users want to see top N contended locks only.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220924004221.841024-1-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 84838712

tools/perf/Documentation/perf-lock.txt

+10 −0
Original line number Diff line number Diff line
@@ -94,6 +94,11 @@ REPORT OPTIONS 
         EventManager_De       1845          1             636

         futex-default-S       1609          0               0



-E::

--entries=<value>::

	Display this many entries.





INFO OPTIONS

------------
@@ -105,6 +110,7 @@ INFO OPTIONS 
--map::

	dump map of lock instances (address:name table)





CONTENTION OPTIONS

--------------
@@ -154,6 +160,10 @@ CONTENTION OPTIONS 
--stack-skip

	Number of stack depth to skip when finding a lock caller (default: 3).



-E::

--entries=<value>::

	Display this many entries.





SEE ALSO

--------

tools/perf/builtin-lock.c

+15 −5
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ static bool use_bpf; 
static unsigned long bpf_map_entries = 10240;

static int max_stack_depth = CONTENTION_STACK_DEPTH;

static int stack_skip = CONTENTION_STACK_SKIP;

static int print_nr_entries = INT_MAX / 2;



static enum {

	LOCK_AGGR_ADDR,
@@ -1266,14 +1267,14 @@ static void print_result(void) 
	struct lock_stat *st;

	struct lock_key *key;

	char cut_name[20];

	int bad, total;

	int bad, total, printed;



	pr_info("%20s ", "Name");

	list_for_each_entry(key, &lock_keys, list)

		pr_info("%*s ", key->len, key->header);

	pr_info("\n\n");



	bad = total = 0;

	bad = total = printed = 0;

	while ((st = pop_from_result())) {

		total++;

		if (st->broken)
@@ -1311,6 +1312,9 @@ static void print_result(void) 
			pr_info(" ");

		}

		pr_info("\n");



		if (++printed >= print_nr_entries)

			break;

	}



	print_bad_events(bad, total);
@@ -1476,7 +1480,7 @@ static void print_contention_result(struct lock_contention *con) 
{

	struct lock_stat *st;

	struct lock_key *key;

	int bad, total;

	int bad, total, printed;



	list_for_each_entry(key, &lock_keys, list)

		pr_info("%*s ", key->len, key->header);
@@ -1486,7 +1490,7 @@ static void print_contention_result(struct lock_contention *con) 
	else

		pr_info("  %10s   %s\n\n", "type", "caller");



	bad = total = 0;

	bad = total = printed = 0;

	if (use_bpf)

		bad = bad_hist[BROKEN_CONTENDED];
@@ -1507,7 +1511,7 @@ static void print_contention_result(struct lock_contention *con) 
			/* st->addr contains tid of thread */

			t = perf_session__findnew(session, pid);

			pr_info("  %10d   %s\n", pid, thread__comm_str(t));

			continue;

			goto next;

		}



		pr_info("  %10s   %s\n", get_type_str(st), st->name);
@@ -1527,6 +1531,10 @@ static void print_contention_result(struct lock_contention *con) 
				pr_info("\t\t\t%#lx  %s\n", (unsigned long)ip, buf);

			}

		}



next:

		if (++printed >= print_nr_entries)

			break;

	}



	print_bad_events(bad, total);
@@ -1878,6 +1886,7 @@ int cmd_lock(int argc, const char **argv) 
		    "combine locks in the same class"),

	OPT_BOOLEAN('t', "threads", &show_thread_stats,

		    "show per-thread lock stats"),

	OPT_INTEGER('E', "entries", &print_nr_entries, "display this many functions"),

	OPT_PARENT(lock_options)

	};
@@ -1905,6 +1914,7 @@ int cmd_lock(int argc, const char **argv) 
	OPT_INTEGER(0, "stack-skip", &stack_skip,

		    "Set the number of stack depth to skip when finding a lock caller, "

		    "Default: " __stringify(CONTENTION_STACK_SKIP)),

	OPT_INTEGER('E', "entries", &print_nr_entries, "display this many functions"),

	OPT_PARENT(lock_options)

	};