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-rw-r--r--src/vlib/threads.c90
1 files changed, 80 insertions, 10 deletions
diff --git a/src/vlib/threads.c b/src/vlib/threads.c
index af60bc6def6..56f9d790ee6 100644
--- a/src/vlib/threads.c
+++ b/src/vlib/threads.c
@@ -1367,7 +1367,9 @@ vlib_worker_thread_barrier_sync_int (vlib_main_t * vm, const char *func_name)
f64 t_entry;
f64 t_open;
f64 t_closed;
+ f64 max_vector_rate, this_vector_rate;
u32 count;
+ int i;
if (vec_len (vlib_mains) < 2)
return;
@@ -1388,23 +1390,44 @@ vlib_worker_thread_barrier_sync_int (vlib_main_t * vm, const char *func_name)
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++)
+ {
+ this_vector_rate =
+ vlib_last_vectors_per_main_loop_as_f64 (vlib_mains[i]);
+ if (max_vector_rate < this_vector_rate)
+ max_vector_rate = this_vector_rate;
+ }
+
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 (1)
+ /*
+ * 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)
{
- 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))
+ while (1)
{
- clib_warning ("clock change: would have waited for %.4f seconds",
- (vm->barrier_no_close_before - now));
- break;
+ 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 */
@@ -1491,6 +1514,14 @@ 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)
@@ -1789,6 +1820,45 @@ 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
*