diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/builtin-record.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 4d4502b7fea0..c69f16361958 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -56,6 +56,9 @@ #include <unistd.h> #include <sched.h> #include <signal.h> +#ifdef HAVE_EVENTFD_SUPPORT +#include <sys/eventfd.h> +#endif #include <sys/mman.h> #include <sys/wait.h> #include <sys/types.h> @@ -538,6 +541,9 @@ static int record__pushfn(struct mmap *map, void *to, void *bf, size_t size) static volatile int signr = -1; static volatile int child_finished; +#ifdef HAVE_EVENTFD_SUPPORT +static int done_fd = -1; +#endif static void sig_handler(int sig) { @@ -547,6 +553,21 @@ static void sig_handler(int sig) signr = sig; done = 1; +#ifdef HAVE_EVENTFD_SUPPORT +{ + u64 tmp = 1; + /* + * It is possible for this signal handler to run after done is checked + * in the main loop, but before the perf counter fds are polled. If this + * happens, the poll() will continue to wait even though done is set, + * and will only break out if either another signal is received, or the + * counters are ready for read. To ensure the poll() doesn't sleep when + * done is set, use an eventfd (done_fd) to wake up the poll(). + */ + if (write(done_fd, &tmp, sizeof(tmp)) < 0) + pr_err("failed to signal wakeup fd, error: %m\n"); +} +#endif // HAVE_EVENTFD_SUPPORT } static void sigsegv_handler(int sig) @@ -1547,6 +1568,20 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) pr_err("Compression initialization failed.\n"); return -1; } +#ifdef HAVE_EVENTFD_SUPPORT + done_fd = eventfd(0, EFD_NONBLOCK); + if (done_fd < 0) { + pr_err("Failed to create wakeup eventfd, error: %m\n"); + status = -1; + goto out_delete_session; + } + err = evlist__add_pollfd(rec->evlist, done_fd); + if (err < 0) { + pr_err("Failed to add wakeup eventfd to poll list\n"); + status = err; + goto out_delete_session; + } +#endif // HAVE_EVENTFD_SUPPORT session->header.env.comp_type = PERF_COMP_ZSTD; session->header.env.comp_level = rec->opts.comp_level; @@ -1905,6 +1940,10 @@ out_child: } out_delete_session: +#ifdef HAVE_EVENTFD_SUPPORT + if (done_fd >= 0) + close(done_fd); +#endif zstd_fini(&session->zstd_data); perf_session__delete(session); |