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: Namhyung 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: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 216a9a2..0593c6e 100644 (file)
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -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;

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 79b9498..918b501 100644 (file)
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -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
-perf-$(CONFIG_PERF_BPF_SKEL) += bpf_lock_contention.o
+
+ifeq ($(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

diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index 286e52b..ead2898 100644 (file)
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -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;
 }

diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h
index 17e594d..39d5bfc 100644 (file)
--- a/tools/perf/util/lock-contention.h
+++ b/tools/perf/util/lock-contention.h
@@ -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