diff options
Diffstat (limited to 'src/vlib/threads.c')
| -rw-r--r-- | src/vlib/threads.c | 83 |
1 files changed, 81 insertions, 2 deletions
diff --git a/src/vlib/threads.c b/src/vlib/threads.c index a946326f239..1119d82bfb8 100644 --- a/src/vlib/threads.c +++ b/src/vlib/threads.c @@ -1448,7 +1448,9 @@ vlib_worker_thread_barrier_sync_int (vlib_main_t * vm) f64 t_entry; f64 t_open; f64 t_closed; + f64 max_vector_rate; u32 count; + int i; if (vec_len (vlib_mains) < 2) return; @@ -1468,13 +1470,43 @@ vlib_worker_thread_barrier_sync_int (vlib_main_t * vm) return; } + /* + * Need data to decide if we're working hard enough to honor + * the barrier hold-down timer. + */ + max_vector_rate = 0.0; + for (i = 1; i < vec_len (vlib_mains); i++) + max_vector_rate = + clib_max (max_vector_rate, + vlib_last_vectors_per_main_loop_as_f64 (vlib_mains[i])); + vlib_worker_threads[0].barrier_sync_count++; /* Enforce minimum barrier open time to minimize packet loss */ ASSERT (vm->barrier_no_close_before <= (now + BARRIER_MINIMUM_OPEN_LIMIT)); - while ((now = vlib_time_now (vm)) < vm->barrier_no_close_before) - ; + /* + * If any worker thread seems busy, which we define + * as a vector rate above 10, we enforce the barrier hold-down timer + */ + if (max_vector_rate > 10.0) + { + while (1) + { + now = vlib_time_now (vm); + /* Barrier hold-down timer expired? */ + if (now >= vm->barrier_no_close_before) + break; + if ((vm->barrier_no_close_before - now) + > (2.0 * BARRIER_MINIMUM_OPEN_LIMIT)) + { + clib_warning + ("clock change: would have waited for %.4f seconds", + (vm->barrier_no_close_before - now)); + break; + } + } + } /* Record time of closure */ t_open = now - vm->barrier_epoch; vm->barrier_epoch = now; @@ -1559,6 +1591,14 @@ vlib_worker_thread_barrier_release (vlib_main_t * vm) deadline = now + BARRIER_SYNC_TIMEOUT; + /* + * Note when we let go of the barrier. + * Workers can use this to derive a reasonably accurate + * time offset. See vlib_time_now(...) + */ + vm->time_last_barrier_release = vlib_time_now (vm); + CLIB_MEMORY_STORE_BARRIER (); + *vlib_worker_threads->wait_at_barrier = 0; while (*vlib_worker_threads->workers_at_barrier > 0) @@ -1844,6 +1884,45 @@ threads_init (vlib_main_t * vm) VLIB_INIT_FUNCTION (threads_init); + +static clib_error_t * +show_clock_command_fn (vlib_main_t * vm, + unformat_input_t * input, vlib_cli_command_t * cmd) +{ + int i; + f64 now; + + now = vlib_time_now (vm); + + vlib_cli_output (vm, "Time now %.9f", now); + + if (vec_len (vlib_mains) == 1) + return 0; + + vlib_cli_output (vm, "Time last barrier release %.9f", + vm->time_last_barrier_release); + + for (i = 1; i < vec_len (vlib_mains); i++) + { + if (vlib_mains[i] == 0) + continue; + vlib_cli_output (vm, "Thread %d offset %.9f error %.9f", i, + vlib_mains[i]->time_offset, + vm->time_last_barrier_release - + vlib_mains[i]->time_last_barrier_release); + } + return 0; +} + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (f_command, static) = +{ + .path = "show clock", + .short_help = "show clock", + .function = show_clock_command_fn, +}; +/* *INDENT-ON* */ + /* * fd.io coding-style-patch-verification: ON * |