Commit 16cad1d3 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf lock contention: Use lock_stat_find{,new} 



This is a preparation work to support complex keys of BPF maps.  Now it
has single value key according to the aggregation mode like stack_id or
pid.  But we want to use a combination of those keys.

Then lock_contention_read() should still aggregate the result based on
the key that was requested by user.  The other key info will be used for
filtering.

So instead of creating a lock_stat entry always, Check if it's already
there using lock_stat_find() first.

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230203021324.143540-3-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 492fef21

tools/perf/builtin-lock.c

+2 −2
Original line number Diff line number Diff line
@@ -465,7 +465,7 @@ static struct lock_stat *pop_from_result(void) 
	return container_of(node, struct lock_stat, rb);

}



static struct lock_stat *lock_stat_find(u64 addr)

struct lock_stat *lock_stat_find(u64 addr)

{

	struct hlist_head *entry = lockhashentry(addr);

	struct lock_stat *ret;
@@ -477,7 +477,7 @@ static struct lock_stat *lock_stat_find(u64 addr) 
	return NULL;

}



static struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags)

struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags)

{

	struct hlist_head *entry = lockhashentry(addr);

	struct lock_stat *ret, *new;

tools/perf/util/Build

+4 −1
Original line number Diff line number Diff line
@@ -154,7 +154,10 @@ perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o 
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o

perf-$(CONFIG_PERF_BPF_SKEL) += bpf_ftrace.o

perf-$(CONFIG_PERF_BPF_SKEL) += bpf_off_cpu.o



ifeq ($(CONFIG_LIBTRACEEVENT),y)

  perf-$(CONFIG_PERF_BPF_SKEL) += bpf_lock_contention.o

endif



ifeq ($(CONFIG_LIBTRACEEVENT),y)

  perf-$(CONFIG_PERF_BPF_SKEL) += bpf_kwork.o

tools/perf/util/bpf_lock_contention.c

+25 −16
Original line number Diff line number Diff line
@@ -256,12 +256,34 @@ int lock_contention_read(struct lock_contention *con) 
	prev_key = NULL;

	while (!bpf_map_get_next_key(fd, prev_key, &key)) {

		s32 stack_id;

		const char *name;



		/* to handle errors in the loop body */

		err = -1;



		bpf_map_lookup_elem(fd, &key, &data);

		st = zalloc(sizeof(*st));



		if (con->save_callstack) {

			stack_id = key.aggr_key;

			bpf_map_lookup_elem(stack, &stack_id, stack_trace);

		}



		st = lock_stat_find(key.aggr_key);

		if (st != NULL) {

			st->wait_time_total += data.total_time;

			if (st->wait_time_max < data.max_time)

				st->wait_time_max = data.max_time;

			if (st->wait_time_min > data.min_time)

				st->wait_time_min = data.min_time;



			st->nr_contended += data.count;

			if (st->nr_contended)

				st->avg_wait_time = st->wait_time_total / st->nr_contended;

			goto next;

		}



		name = lock_contention_get_name(con, &key, stack_trace);

		st = lock_stat_findnew(key.aggr_key, name, data.flags);

		if (st == NULL)

			break;
@@ -274,14 +296,6 @@ int lock_contention_read(struct lock_contention *con) 
			st->avg_wait_time = data.total_time / data.count;



		st->flags = data.flags;

		st->addr = key.aggr_key;



		stack_id = key.aggr_key;

		bpf_map_lookup_elem(stack, &stack_id, stack_trace);



		st->name = strdup(lock_contention_get_name(con, &key, stack_trace));

		if (st->name == NULL)

			break;



		if (con->save_callstack) {

			st->callstack = memdup(stack_trace, stack_size);
@@ -289,19 +303,14 @@ int lock_contention_read(struct lock_contention *con) 
				break;

		}



		hlist_add_head(&st->hash_entry, con->result);

next:

		prev_key = &key;



		/* we're fine now, reset the values */

		st = NULL;

		/* we're fine now, reset the error */

		err = 0;

	}



	free(stack_trace);

	if (st) {

		free(st->name);

		free(st);

	}



	return err;

}

tools/perf/util/lock-contention.h

+3 −0
Original line number Diff line number Diff line
@@ -65,6 +65,9 @@ struct lock_stat { 
 */

#define MAX_LOCK_DEPTH 48



struct lock_stat *lock_stat_find(u64 addr);

struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags);



/*

 * struct lock_seq_stat:

 * Place to put on state of one lock sequence