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Date: Fri, 9 Dec 2022 11:07:26 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Arnaldo Carvalho de Melo <acme@...nel.org>,
Jiri Olsa <jolsa@...nel.org>
Cc: Ingo Molnar <mingo@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
LKML <linux-kernel@...r.kernel.org>,
Ian Rogers <irogers@...gle.com>,
Adrian Hunter <adrian.hunter@...el.com>,
linux-perf-users@...r.kernel.org, Song Liu <song@...nel.org>,
Blake Jones <blakejones@...gle.com>, bpf@...r.kernel.org
Subject: [PATCH 3/4] perf lock contention: Add -l/--lock-addr option
The -l/--lock-addr option is to implement per-lock-instance contention
stat using LOCK_AGGR_ADDR. It displays lock address and optionally
symbol name if exists.
$ sudo ./perf lock con -abl sleep 1
contended total wait max wait avg wait address symbol
1 36.28 us 36.28 us 36.28 us ffff92615d6448b8
9 10.91 us 1.84 us 1.21 us ffffffffbaed50c0 rcu_state
1 10.49 us 10.49 us 10.49 us ffff9262ac4f0c80
8 4.68 us 1.67 us 585 ns ffffffffbae07a40 jiffies_lock
3 3.03 us 1.45 us 1.01 us ffff9262277861e0
1 924 ns 924 ns 924 ns ffff926095ba9d20
1 436 ns 436 ns 436 ns ffff9260bfda4f60
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
tools/perf/Documentation/perf-lock.txt | 4 +
tools/perf/builtin-lock.c | 84 +++++++++++++++----
tools/perf/util/bpf_lock_contention.c | 23 +++--
.../perf/util/bpf_skel/lock_contention.bpf.c | 17 +++-
tools/perf/util/bpf_skel/lock_data.h | 2 +-
5 files changed, 102 insertions(+), 28 deletions(-)
diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt
index 4958a1ffa1cc..38e79d45e426 100644
--- a/tools/perf/Documentation/perf-lock.txt
+++ b/tools/perf/Documentation/perf-lock.txt
@@ -168,6 +168,10 @@ CONTENTION OPTIONS
--entries=<value>::
Display this many entries.
+-l::
+--lock-addr::
+ Show lock contention stat by address
+
SEE ALSO
--------
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 6fa3cdfec5cb..25c0a5e5051f 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -56,6 +56,7 @@ static struct rb_root thread_stats;
static bool combine_locks;
static bool show_thread_stats;
+static bool show_lock_addrs;
static bool use_bpf;
static unsigned long bpf_map_entries = 10240;
static int max_stack_depth = CONTENTION_STACK_DEPTH;
@@ -999,13 +1000,32 @@ static int report_lock_contention_begin_event(struct evsel *evsel,
ls = lock_stat_find(key);
if (!ls) {
char buf[128];
- const char *caller = buf;
+ const char *name = "";
unsigned int flags = evsel__intval(evsel, sample, "flags");
+ struct machine *machine = &session->machines.host;
+ struct map *kmap;
+ struct symbol *sym;
+
+ switch (aggr_mode) {
+ case LOCK_AGGR_ADDR:
+ /* make sure it loads the kernel map to find lock symbols */
+ map__load(machine__kernel_map(machine));
+
+ sym = machine__find_kernel_symbol(machine, key, &kmap);
+ if (sym)
+ name = sym->name;
+ break;
+ case LOCK_AGGR_CALLER:
+ name = buf;
+ if (lock_contention_caller(evsel, sample, buf, sizeof(buf)) < 0)
+ name = "Unknown";
+ break;
+ case LOCK_AGGR_TASK:
+ default:
+ break;
+ }
- if (lock_contention_caller(evsel, sample, buf, sizeof(buf)) < 0)
- caller = "Unknown";
-
- ls = lock_stat_findnew(key, caller, flags);
+ ls = lock_stat_findnew(key, name, flags);
if (!ls)
return -ENOMEM;
@@ -1460,10 +1480,19 @@ static void print_contention_result(struct lock_contention *con)
list_for_each_entry(key, &lock_keys, list)
pr_info("%*s ", key->len, key->header);
- if (show_thread_stats)
+ switch (aggr_mode) {
+ case LOCK_AGGR_TASK:
pr_info(" %10s %s\n\n", "pid", "comm");
- else
+ break;
+ case LOCK_AGGR_CALLER:
pr_info(" %10s %s\n\n", "type", "caller");
+ break;
+ case LOCK_AGGR_ADDR:
+ pr_info(" %16s %s\n\n", "address", "symbol");
+ break;
+ default:
+ break;
+ }
}
bad = total = printed = 0;
@@ -1471,6 +1500,9 @@ static void print_contention_result(struct lock_contention *con)
bad = bad_hist[BROKEN_CONTENDED];
while ((st = pop_from_result())) {
+ struct thread *t;
+ int pid;
+
total += use_bpf ? st->nr_contended : 1;
if (st->broken)
bad++;
@@ -1480,18 +1512,24 @@ static void print_contention_result(struct lock_contention *con)
pr_info(" ");
}
- if (show_thread_stats) {
- struct thread *t;
- int pid = st->addr;
-
- /* st->addr contains tid of thread */
+ switch (aggr_mode) {
+ case LOCK_AGGR_CALLER:
+ pr_info(" %10s %s\n", get_type_str(st), st->name);
+ break;
+ case LOCK_AGGR_TASK:
+ pid = st->addr;
t = perf_session__findnew(session, pid);
pr_info(" %10d %s\n", pid, thread__comm_str(t));
- goto next;
+ break;
+ case LOCK_AGGR_ADDR:
+ pr_info(" %016llx %s\n", (unsigned long long)st->addr,
+ st->name ? : "");
+ break;
+ default:
+ break;
}
- pr_info(" %10s %s\n", get_type_str(st), st->name);
- if (verbose) {
+ if (aggr_mode == LOCK_AGGR_CALLER && verbose) {
struct map *kmap;
struct symbol *sym;
char buf[128];
@@ -1508,7 +1546,6 @@ static void print_contention_result(struct lock_contention *con)
}
}
-next:
if (++printed >= print_nr_entries)
break;
}
@@ -1616,7 +1653,6 @@ static int __cmd_contention(int argc, const char **argv)
.map_nr_entries = bpf_map_entries,
.max_stack = max_stack_depth,
.stack_skip = stack_skip,
- .aggr_mode = show_thread_stats ? LOCK_AGGR_TASK : LOCK_AGGR_CALLER,
};
session = perf_session__new(use_bpf ? NULL : &data, &eops);
@@ -1627,6 +1663,9 @@ static int __cmd_contention(int argc, const char **argv)
con.machine = &session->machines.host;
+ con.aggr_mode = aggr_mode = show_thread_stats ? LOCK_AGGR_TASK :
+ show_lock_addrs ? LOCK_AGGR_ADDR : LOCK_AGGR_CALLER;
+
/* for lock function check */
symbol_conf.sort_by_name = true;
symbol__init(&session->header.env);
@@ -1907,6 +1946,7 @@ int cmd_lock(int argc, const char **argv)
"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_BOOLEAN('l', "lock-addr", &show_lock_addrs, "show lock stats by address"),
OPT_PARENT(lock_options)
};
@@ -1976,6 +2016,16 @@ int cmd_lock(int argc, const char **argv)
argc = parse_options(argc, argv, contention_options,
contention_usage, 0);
}
+
+ if (show_thread_stats && show_lock_addrs) {
+ pr_err("Cannot use thread and addr mode together\n");
+ parse_options_usage(contention_usage, contention_options,
+ "threads", 0);
+ parse_options_usage(NULL, contention_options,
+ "lock-addr", 0);
+ return -1;
+ }
+
rc = __cmd_contention(argc, argv);
} else {
usage_with_options(lock_usage, lock_options);
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index 1590a9f05145..8e1b791dc58f 100644
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -137,11 +137,15 @@ int lock_contention_read(struct lock_contention *con)
thread__set_comm(idle, "swapper", /*timestamp=*/0);
}
+ /* make sure it loads the kernel map */
+ map__load(maps__first(machine->kmaps));
+
prev_key = NULL;
while (!bpf_map_get_next_key(fd, prev_key, &key)) {
struct map *kmap;
struct symbol *sym;
int idx = 0;
+ s32 stack_id;
/* to handle errors in the loop body */
err = -1;
@@ -160,24 +164,31 @@ 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;
if (con->aggr_mode == LOCK_AGGR_TASK) {
struct contention_task_data task;
struct thread *t;
-
- st->addr = key.stack_or_task_id;
+ int pid = key.aggr_key;
/* do not update idle comm which contains CPU number */
if (st->addr) {
- bpf_map_lookup_elem(task_fd, &key, &task);
- t = __machine__findnew_thread(machine, /*pid=*/-1,
- key.stack_or_task_id);
+ bpf_map_lookup_elem(task_fd, &pid, &task);
+ t = __machine__findnew_thread(machine, /*pid=*/-1, pid);
thread__set_comm(t, task.comm, /*timestamp=*/0);
}
goto next;
}
- bpf_map_lookup_elem(stack, &key, stack_trace);
+ if (con->aggr_mode == LOCK_AGGR_ADDR) {
+ sym = machine__find_kernel_symbol(machine, st->addr, &kmap);
+ if (sym)
+ st->name = strdup(sym->name);
+ goto next;
+ }
+
+ stack_id = key.aggr_key;
+ bpf_map_lookup_elem(stack, &stack_id, stack_trace);
/* skip lock internal functions */
while (machine__is_lock_function(machine, stack_trace[idx]) &&
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
index cd405adcd252..11b0fc7ee53b 100644
--- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
+++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
@@ -168,11 +168,20 @@ int contention_end(u64 *ctx)
duration = bpf_ktime_get_ns() - pelem->timestamp;
- if (aggr_mode == LOCK_AGGR_CALLER) {
- key.stack_or_task_id = pelem->stack_id;
- } else {
- key.stack_or_task_id = pid;
+ switch (aggr_mode) {
+ case LOCK_AGGR_CALLER:
+ key.aggr_key = pelem->stack_id;
+ break;
+ case LOCK_AGGR_TASK:
+ key.aggr_key = pid;
update_task_data(pid);
+ break;
+ case LOCK_AGGR_ADDR:
+ key.aggr_key = pelem->lock;
+ break;
+ default:
+ /* should not happen */
+ return 0;
}
data = bpf_map_lookup_elem(&lock_stat, &key);
diff --git a/tools/perf/util/bpf_skel/lock_data.h b/tools/perf/util/bpf_skel/lock_data.h
index dbdf4caedc4a..ce71cf1a7e1e 100644
--- a/tools/perf/util/bpf_skel/lock_data.h
+++ b/tools/perf/util/bpf_skel/lock_data.h
@@ -4,7 +4,7 @@
#define UTIL_BPF_SKEL_LOCK_DATA_H
struct contention_key {
- s32 stack_or_task_id;
+ u64 aggr_key; /* can be stack_id, pid or lock addr */
};
#define TASK_COMM_LEN 16
--
2.39.0.rc1.256.g54fd8350bd-goog
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