diff options
| author |   Dave Barach <dave@barachs.net> | 2019-04-23 10:07:24 -0400 |
|---|---|---|
| committer |   Dave Barach <openvpp@barachs.net> | 2019-05-01 23:51:20 +0000 |
| commit | 79ad20fc043d74b8812824d0862292bc83e9b09a (patch) | |
| tree | e97ed7a7a8c4b8bcb26f394bd78af63e04f87abe /src/vlib/threads.c | |
| parent | 7cbf2d154acc53609afdc76a8bef1c4023fe274a (diff) | |
Clean up multi-thread barrier-sync hold-down timer
Main thread: don't bother with the barrier sync hold-down timer if
none of the worker threads are busy.
Worker threads: avoid epoll_pwait (10ms timeout) when the
control-plane has been active in the last half-second.
Change-Id: I82008d09968c65e2a4af0ebb7887389992e60603
Signed-off-by: Dave Barach <dave@barachs.net>
(cherry picked from commit 9ae190e9d228bfc1358482d4f07da1f4cfd41c90)
Diffstat (limited to 'src/vlib/threads.c')
| -rw-r--r-- | src/vlib/threads.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/src/vlib/threads.c b/src/vlib/threads.c index 7d17c7b37cc..52886df37e0 100644 --- a/src/vlib/threads.c +++ b/src/vlib/threads.c @@ -1389,7 +1389,9 @@ 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; u32 count; + int i; if (vec_len (vlib_mains) < 2) return; @@ -1410,23 +1412,41 @@ 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++) + 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 (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 */ |