This is a note to let you know that I've just added the patch titled perf stat: Close cork_fd when create_perf_stat_counter() failed to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-stat-close-cork_fd-when-create_perf_stat_counte.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8187b5438e5ba50e1bfc49347228c13ce382193e Author: Levi Yun <yeoreum.yun@xxxxxxx> Date: Wed Sep 25 14:20:21 2024 +0100 perf stat: Close cork_fd when create_perf_stat_counter() failed [ Upstream commit e880a70f8046df0dd9089fa60dcb866a2cc69194 ] When create_perf_stat_counter() failed, it doesn't close workload.cork_fd open in evlist__prepare_workload(). This could make too many open file error while __run_perf_stat() repeats. Introduce evlist__cancel_workload to close workload.cork_fd and wait workload.child_pid until exit to clear child process when create_perf_stat_counter() is failed. Signed-off-by: Levi Yun <yeoreum.yun@xxxxxxx> Reviewed-by: James Clark <james.clark@xxxxxxxxxx> Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: nd@xxxxxxx Cc: howardchu95@xxxxxxxxx Link: https://lore.kernel.org/r/20240925132022.2650180-2-yeoreum.yun@xxxxxxx Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> Stable-dep-of: 7f6ccb70e465 ("perf stat: Fix affinity memory leaks on error path") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index bdd8dd54fdb63..79e058ff8a33a 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -756,15 +756,19 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) evlist__set_leader(evsel_list); if (!cpu_map__is_dummy(evsel_list->core.user_requested_cpus)) { - if (affinity__setup(&saved_affinity) < 0) - return -1; + if (affinity__setup(&saved_affinity) < 0) { + err = -1; + goto err_out; + } affinity = &saved_affinity; } evlist__for_each_entry(evsel_list, counter) { counter->reset_group = false; - if (bpf_counter__load(counter, &target)) - return -1; + if (bpf_counter__load(counter, &target)) { + err = -1; + goto err_out; + } if (!(evsel__is_bperf(counter))) all_counters_use_bpf = false; } @@ -805,7 +809,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) switch (stat_handle_error(counter)) { case COUNTER_FATAL: - return -1; + err = -1; + goto err_out; case COUNTER_RETRY: goto try_again; case COUNTER_SKIP: @@ -846,7 +851,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) switch (stat_handle_error(counter)) { case COUNTER_FATAL: - return -1; + err = -1; + goto err_out; case COUNTER_RETRY: goto try_again_reset; case COUNTER_SKIP: @@ -871,8 +877,10 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) stat_config.unit_width = l; if (evsel__should_store_id(counter) && - evsel__store_ids(counter, evsel_list)) - return -1; + evsel__store_ids(counter, evsel_list)) { + err = -1; + goto err_out; + } } if (evlist__apply_filters(evsel_list, &counter)) { @@ -893,20 +901,23 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) } if (err < 0) - return err; + goto err_out; err = perf_event__synthesize_stat_events(&stat_config, NULL, evsel_list, process_synthesized_event, is_pipe); if (err < 0) - return err; + goto err_out; + } if (target.initial_delay) { pr_info(EVLIST_DISABLED_MSG); } else { err = enable_counters(); - if (err) - return -1; + if (err) { + err = -1; + goto err_out; + } } /* Exec the command, if any */ @@ -916,8 +927,10 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) if (target.initial_delay > 0) { usleep(target.initial_delay * USEC_PER_MSEC); err = enable_counters(); - if (err) - return -1; + if (err) { + err = -1; + goto err_out; + } pr_info(EVLIST_ENABLED_MSG); } @@ -937,7 +950,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) if (workload_exec_errno) { const char *emsg = str_error_r(workload_exec_errno, msg, sizeof(msg)); pr_err("Workload failed: %s\n", emsg); - return -1; + err = -1; + goto err_out; } if (WIFSIGNALED(status)) @@ -986,6 +1000,12 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) evlist__close(evsel_list); return WEXITSTATUS(status); + +err_out: + if (forks) + evlist__cancel_workload(evsel_list); + + return err; } static int run_perf_stat(int argc, const char **argv, int run_idx) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index ca08e6dc8b232..dca6843ea3225 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -42,6 +42,7 @@ #include <sys/mman.h> #include <sys/prctl.h> #include <sys/timerfd.h> +#include <sys/wait.h> #include <linux/bitops.h> #include <linux/hash.h> @@ -1392,6 +1393,8 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const int child_ready_pipe[2], go_pipe[2]; char bf; + evlist->workload.cork_fd = -1; + if (pipe(child_ready_pipe) < 0) { perror("failed to create 'ready' pipe"); return -1; @@ -1444,7 +1447,7 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const * For cancelling the workload without actually running it, * the parent will just close workload.cork_fd, without writing * anything, i.e. read will return zero and we just exit() - * here. + * here (See evlist__cancel_workload()). */ if (ret != 1) { if (ret == -1) @@ -1508,7 +1511,7 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const int evlist__start_workload(struct evlist *evlist) { - if (evlist->workload.cork_fd > 0) { + if (evlist->workload.cork_fd >= 0) { char bf = 0; int ret; /* @@ -1519,12 +1522,24 @@ int evlist__start_workload(struct evlist *evlist) perror("unable to write to pipe"); close(evlist->workload.cork_fd); + evlist->workload.cork_fd = -1; return ret; } return 0; } +void evlist__cancel_workload(struct evlist *evlist) +{ + int status; + + if (evlist->workload.cork_fd >= 0) { + close(evlist->workload.cork_fd); + evlist->workload.cork_fd = -1; + waitpid(evlist->workload.pid, &status, WNOHANG); + } +} + int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct perf_sample *sample) { struct evsel *evsel = evlist__event2evsel(evlist, event); diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 16734c6756b3c..dc2197069cdc6 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -187,6 +187,7 @@ int evlist__prepare_workload(struct evlist *evlist, struct target *target, const char *argv[], bool pipe_output, void (*exec_error)(int signo, siginfo_t *info, void *ucontext)); int evlist__start_workload(struct evlist *evlist); +void evlist__cancel_workload(struct evlist *evlist); struct option;