[v2,2/3] perf lock contention: Use lock_stat_find{,new}
Commit Message
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>
---
tools/perf/builtin-lock.c | 4 +--
tools/perf/util/Build | 5 +++-
tools/perf/util/bpf_lock_contention.c | 41 ++++++++++++++++-----------
tools/perf/util/lock-contention.h | 3 ++
4 files changed, 34 insertions(+), 19 deletions(-)
@@ -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;
@@ -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
@@ -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;
}
@@ -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