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perf lock contention: Filter events before creating lock_stat

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In report_lock_contention_begin_event(), lock_stat_findnew() was
called before checking filters.nr_types (-Y), filters.nr_addrs (-L),
and match_callstack_filter() (-S).

When a filtered-out lock event (such as a mutex contention when
running with -Y spinlock) shared the same aggregation key as a
subsequent matching event (for example, contention on the mutex's
internal wait_lock spinlock from the same caller), the first event
created the lock_stat entry with the filtered-out lock's flags and the
second event reused that entry, causing non-spinlock entries to appear
in -Y spinlock output.

Check the type, address, and callstack filters before looking up or
creating the lock_stat entry.

Fixes: b4a7eff93c ("perf lock contention: Add -Y/--type-filter option")
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers 2026-10-20 13:58:51 -07:00 committed by Arnaldo Carvalho de Melo
parent 746cd5440b
commit c58d1598e7
1 changed files with 33 additions and 28 deletions
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61
tools/perf/builtin-lock.c
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@ -975,6 +975,7 @@ static int report_lock_contention_begin_event(struct perf_sample *sample)
struct machine *machine = &session->machines.host;
struct map *kmap;
struct symbol *sym;
u64 *callstack = NULL;
ret = get_key_by_aggr_mode(&key, addr, sample);
if (ret < 0)
@ -1010,33 +1011,6 @@ static int report_lock_contention_begin_event(struct perf_sample *sample)
}
}
ls = lock_stat_find(key);
if (!ls) {
char buf[128];
const char *name = "";
switch (aggr_mode) {
case LOCK_AGGR_ADDR:
sym = machine__find_kernel_symbol(machine, key, &kmap);
if (sym)
name = sym->name;
break;
case LOCK_AGGR_CALLER:
name = buf;
if (lock_contention_caller(sample, buf, sizeof(buf)) < 0)
name = "Unknown";
break;
case LOCK_AGGR_CGROUP:
case LOCK_AGGR_TASK:
default:
break;
}
ls = lock_stat_findnew(key, name, flags);
if (!ls)
return -ENOMEM;
}
if (filters.nr_types) {
bool found = false;
@ -1066,7 +1040,7 @@ static int report_lock_contention_begin_event(struct perf_sample *sample)
}
if (needs_callstack()) {
u64 *callstack = get_callstack(sample, max_stack_depth);
callstack = get_callstack(sample, max_stack_depth);
if (callstack == NULL)
return 0;
@ -1074,7 +1048,38 @@ static int report_lock_contention_begin_event(struct perf_sample *sample)
free(callstack);
return 0;
}
}
ls = lock_stat_find(key);
if (!ls) {
char buf[128];
const char *name = "";
switch (aggr_mode) {
case LOCK_AGGR_ADDR:
sym = machine__find_kernel_symbol(machine, key, &kmap);
if (sym)
name = sym->name;
break;
case LOCK_AGGR_CALLER:
name = buf;
if (lock_contention_caller(sample, buf, sizeof(buf)) < 0)
name = "Unknown";
break;
case LOCK_AGGR_CGROUP:
case LOCK_AGGR_TASK:
default:
break;
}
ls = lock_stat_findnew(key, name, flags);
if (!ls) {
free(callstack);
return -ENOMEM;
}
}
if (callstack) {
if (ls->callstack == NULL)
ls->callstack = callstack;
else