Currently it shows a caller function for each entry, but users need to see
the full call stacks sometimes. Use -v/--verbose option to do that.
# perf lock con -a -b -v sleep 3
Looking at the vmlinux_path (8 entries long)
symsrc__init: cannot get elf header.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
contended total wait max wait avg wait type caller
1 10.74 us 10.74 us 10.74 us spinlock __bpf_trace_contention_begin+0xb
0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
0xffffffffbb8b8e75 bpf_trace_run2+0x35
0xffffffffbb7eab9b __bpf_trace_contention_begin+0xb
0xffffffffbb7ebe75 queued_spin_lock_slowpath+0x1f5
0xffffffffbc1c26ff _raw_spin_lock+0x1f
0xffffffffbb841015 tick_do_update_jiffies64+0x25
0xffffffffbb8409ee tick_irq_enter+0x9e
1 7.70 us 7.70 us 7.70 us spinlock __bpf_trace_contention_begin+0xb
0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
0xffffffffc03b5c47 bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
0xffffffffbb8b8e75 bpf_trace_run2+0x35
0xffffffffbb7eab9b __bpf_trace_contention_begin+0xb
0xffffffffbb7ebe75 queued_spin_lock_slowpath+0x1f5
0xffffffffbc1c26ff _raw_spin_lock+0x1f
0xffffffffbb7bc27e raw_spin_rq_lock_nested+0xe
0xffffffffbb7cef9c load_balance+0x66c
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-lock.c | 51 ++++++++++++++++++++++++---
tools/perf/util/bpf_lock_contention.c | 9 +++++
tools/perf/util/lock-contention.h | 1 +
3 files changed, 57 insertions(+), 4 deletions(-)
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index eaba6018da69..371539049358 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -1014,6 +1014,27 @@ static u64 callchain_id(struct evsel *evsel, struct perf_sample *sample)
return hash;
}
+static u64 *get_callstack(struct perf_sample *sample, int max_stack)
+{
+ u64 *callstack;
+ u64 i;
+ int c;
+
+ callstack = calloc(max_stack, sizeof(*callstack));
+ if (callstack == NULL)
+ return NULL;
+
+ for (i = 0, c = 0; i < sample->callchain->nr && c < max_stack; i++) {
+ u64 ip = sample->callchain->ips[i];
+
+ if (ip >= PERF_CONTEXT_MAX)
+ continue;
+
+ callstack[c++] = ip;
+ }
+ return callstack;
+}
+
static int report_lock_contention_begin_event(struct evsel *evsel,
struct perf_sample *sample)
{
@@ -1040,6 +1061,12 @@ static int report_lock_contention_begin_event(struct evsel *evsel,
ls = lock_stat_findnew(key, caller, flags);
if (!ls)
return -ENOMEM;
+
+ if (aggr_mode == LOCK_AGGR_CALLER && verbose) {
+ ls->callstack = get_callstack(sample, CONTENTION_STACK_DEPTH);
+ if (ls->callstack == NULL)
+ return -ENOMEM;
+ }
}
ts = thread_stat_findnew(sample->tid);
@@ -1443,7 +1470,7 @@ static void sort_contention_result(void)
sort_result();
}
-static void print_contention_result(void)
+static void print_contention_result(struct lock_contention *con)
{
struct lock_stat *st;
struct lock_key *key;
@@ -1482,6 +1509,22 @@ static void print_contention_result(void)
}
pr_info(" %10s %s\n", get_type_str(st), st->name);
+ if (verbose) {
+ struct map *kmap;
+ struct symbol *sym;
+ char buf[128];
+ u64 ip;
+
+ for (int i = 0; i < CONTENTION_STACK_DEPTH; i++) {
+ if (!st->callstack || !st->callstack[i])
+ break;
+
+ ip = st->callstack[i];
+ sym = machine__find_kernel_symbol(con->machine, ip, &kmap);
+ get_symbol_name_offset(kmap, sym, ip, buf, sizeof(buf));
+ pr_info("\t\t\t%#lx %s\n", (unsigned long)ip, buf);
+ }
+ }
}
print_bad_events(bad, total);
@@ -1597,6 +1640,8 @@ static int __cmd_contention(int argc, const char **argv)
return PTR_ERR(session);
}
+ con.machine = &session->machines.host;
+
/* for lock function check */
symbol_conf.sort_by_name = true;
symbol__init(&session->header.env);
@@ -1615,8 +1660,6 @@ static int __cmd_contention(int argc, const char **argv)
signal(SIGCHLD, sighandler);
signal(SIGTERM, sighandler);
- con.machine = &session->machines.host;
-
con.evlist = evlist__new();
if (con.evlist == NULL) {
err = -ENOMEM;
@@ -1688,7 +1731,7 @@ static int __cmd_contention(int argc, const char **argv)
setup_pager();
sort_contention_result();
- print_contention_result();
+ print_contention_result(&con);
out_delete:
evlist__delete(con.evlist);
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index c591a66733ef..6545bee65347 100644
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -8,6 +8,7 @@
#include "util/thread_map.h"
#include "util/lock-contention.h"
#include <linux/zalloc.h>
+#include <linux/string.h>
#include <bpf/bpf.h>
#include "bpf_skel/lock_contention.skel.h"
@@ -171,6 +172,14 @@ int lock_contention_read(struct lock_contention *con)
return -1;
}
+ if (verbose) {
+ st->callstack = memdup(stack_trace, sizeof(stack_trace));
+ if (st->callstack == NULL) {
+ free(st);
+ return -1;
+ }
+ }
+
hlist_add_head(&st->hash_entry, con->result);
prev_key = key;
}
diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h
index 2146efc33396..bdb6e2a61e5b 100644
--- a/tools/perf/util/lock-contention.h
+++ b/tools/perf/util/lock-contention.h
@@ -11,6 +11,7 @@ struct lock_stat {
u64 addr; /* address of lockdep_map, used as ID */
char *name; /* for strcpy(), we cannot use const */
+ u64 *callstack;
unsigned int nr_acquire;
unsigned int nr_acquired;
--
2.37.2.789.g6183377224-goog
