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perf lock contention: Use lock_stat_find{,new}

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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>
This commit is contained in:
Namhyung Kim 2023-02-02 18:13:23 -08:00 committed by Arnaldo Carvalho de Melo
parent 492fef218a
commit 16cad1d359
4 changed files with 34 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
tools/perf/builtin-lock.c
View File

@ -465,7 +465,7 @@ static struct lock_stat *pop_from_result(void)
return container_of(node, struct lock_stat, rb); 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 hlist_head *entry = lockhashentry(addr);
struct lock_stat *ret; struct lock_stat *ret;
@ -477,7 +477,7 @@ static struct lock_stat *lock_stat_find(u64 addr)
return NULL; 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 hlist_head *entry = lockhashentry(addr);
struct lock_stat *ret, *new; struct lock_stat *ret, *new;

5
tools/perf/util/Build
View File

@ -154,7 +154,10 @@ perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_ftrace.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_ftrace.o
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_off_cpu.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 ($(CONFIG_LIBTRACEEVENT),y) ifeq ($(CONFIG_LIBTRACEEVENT),y)
perf-$(CONFIG_PERF_BPF_SKEL) += bpf_kwork.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_kwork.o

41
tools/perf/util/bpf_lock_contention.c
View File

@ -256,12 +256,34 @@ int lock_contention_read(struct lock_contention *con)
prev_key = NULL; prev_key = NULL;
while (!bpf_map_get_next_key(fd, prev_key, &key)) { while (!bpf_map_get_next_key(fd, prev_key, &key)) {
s32 stack_id; s32 stack_id;
const char *name;
/* to handle errors in the loop body */ /* to handle errors in the loop body */
err = -1; err = -1;
bpf_map_lookup_elem(fd, &key, &data); 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) if (st == NULL)
break; break;
@ -274,14 +296,6 @@ int lock_contention_read(struct lock_contention *con)
st->avg_wait_time = data.total_time / data.count; st->avg_wait_time = data.total_time / data.count;
st->flags = data.flags; 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) { if (con->save_callstack) {
st->callstack = memdup(stack_trace, stack_size); st->callstack = memdup(stack_trace, stack_size);
@ -289,19 +303,14 @@ int lock_contention_read(struct lock_contention *con)
break; break;
} }
hlist_add_head(&st->hash_entry, con->result); next:
prev_key = &key; prev_key = &key;
/* we're fine now, reset the values */ /* we're fine now, reset the error */
st = NULL;
err = 0; err = 0;
} }
free(stack_trace); free(stack_trace);
if (st) {
free(st->name);
free(st);
}
return err; return err;
} }

3
tools/perf/util/lock-contention.h
View File

@ -65,6 +65,9 @@ struct lock_stat {
*/ */
#define MAX_LOCK_DEPTH 48 #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: * struct lock_seq_stat:
* Place to put on state of one lock sequence * Place to put on state of one lock sequence