diff options
| -rw-r--r-- | src/libsystemd/sd-event/sd-event.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c index 7fccbd1a71..03ceac3676 100644 --- a/src/libsystemd/sd-event/sd-event.c +++ b/src/libsystemd/sd-event/sd-event.c @@ -225,6 +225,7 @@ struct sd_event { bool exit_requested:1; bool need_process_child:1; bool watchdog:1; + bool profile_delays:1; int exit_code; @@ -236,6 +237,9 @@ struct sd_event { unsigned n_sources; LIST_HEAD(sd_event_source, sources); + + usec_t last_run, last_log; + unsigned delays[sizeof(usec_t) * 8]; }; static void source_disconnect(sd_event_source *s); @@ -444,6 +448,11 @@ _public_ int sd_event_new(sd_event** ret) { goto fail; } + if (secure_getenv("SD_EVENT_PROFILE_DELAYS")) { + log_info("Event loop profiling enabled. Logarithmic histogram of event loop iterations in the range 2^0 ... 2^63 us will be logged every 5s."); + e->profile_delays = true; + } + *ret = e; return 0; @@ -2622,6 +2631,17 @@ _public_ int sd_event_dispatch(sd_event *e) { return 1; } +static void event_log_delays(sd_event *e) { + char b[ELEMENTSOF(e->delays) * DECIMAL_STR_MAX(unsigned) + 1]; + int i, o; + + for (i = o = 0; i < ELEMENTSOF(e->delays); i++) { + o += snprintf(&b[o], sizeof(b) - o, "%u ", e->delays[i]); + e->delays[i] = 0; + } + log_info("Event loop iterations: %.*s", o, b); +} + _public_ int sd_event_run(sd_event *e, uint64_t timeout) { int r; @@ -2630,11 +2650,30 @@ _public_ int sd_event_run(sd_event *e, uint64_t timeout) { assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); assert_return(e->state == SD_EVENT_INITIAL, -EBUSY); + if (e->profile_delays && e->last_run) { + usec_t this_run; + unsigned l; + + this_run = now(CLOCK_MONOTONIC); + + l = u64log2(this_run - e->last_run); + assert(l < sizeof(e->delays)); + e->delays[l]++; + + if (this_run - e->last_log >= 5*USEC_PER_SEC) { + event_log_delays(e); + e->last_log = this_run; + } + } + r = sd_event_prepare(e); if (r == 0) /* There was nothing? Then wait... */ r = sd_event_wait(e, timeout); + if (e->profile_delays) + e->last_run = now(CLOCK_MONOTONIC); + if (r > 0) { /* There's something now, then let's dispatch it */ r = sd_event_dispatch(e); |