From: Florin Coras <fcoras@cisco.com>
Date: Wed, 5 Jun 2019 17:47:16 +0000 (-0700)
Subject: vcl: cap epoll dequeue batch size to max events
X-Git-Tag: v20.01-rc0~465
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F87%2F19987%2F5;p=vpp.git

vcl: cap epoll dequeue batch size to max events

Type: fix

Change-Id: Ia9be1413cf9423552137885521cefdbecc3e5df5
Signed-off-by: Florin Coras <fcoras@cisco.com>
Signed-off-by: Ping Yu <ping.yu@intel.com>
---

diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 1641beee9f6..8b81e260298 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -44,13 +44,13 @@ vcl_wait_for_segment (u64 segment_handle)
 }
 
 static inline int
-vcl_mq_dequeue_batch (vcl_worker_t * wrk, svm_msg_q_t * mq)
+vcl_mq_dequeue_batch (vcl_worker_t * wrk, svm_msg_q_t * mq, u32 n_max_msg)
 {
   svm_msg_q_msg_t *msg;
   u32 n_msgs;
   int i;
 
-  n_msgs = svm_msg_q_size (mq);
+  n_msgs = clib_min (svm_msg_q_size (mq), n_max_msg);
   for (i = 0; i < n_msgs; i++)
     {
       vec_add2 (wrk->mq_msg_vector, msg, 1);
@@ -764,7 +764,7 @@ vcl_flush_mq_events (void)
 
   mq = wrk->app_event_queue;
   svm_msg_q_lock (mq);
-  vcl_mq_dequeue_batch (wrk, mq);
+  vcl_mq_dequeue_batch (wrk, mq, ~0);
   svm_msg_q_unlock (mq);
 
   for (i = 0; i < vec_len (wrk->mq_msg_vector); i++)
@@ -1895,7 +1895,7 @@ vcl_select_handle_mq (vcl_worker_t * wrk, svm_msg_q_t * mq,
 	    }
 	}
     }
-  vcl_mq_dequeue_batch (wrk, mq);
+  vcl_mq_dequeue_batch (wrk, mq, ~0);
   svm_msg_q_unlock (mq);
 
   for (i = 0; i < vec_len (wrk->mq_msg_vector); i++)
@@ -2479,7 +2479,8 @@ vcl_epoll_wait_handle_mq (vcl_worker_t * wrk, svm_msg_q_t * mq,
 	    }
 	}
     }
-  vcl_mq_dequeue_batch (wrk, mq);
+  ASSERT (maxevents > *num_ev);
+  vcl_mq_dequeue_batch (wrk, mq, maxevents - *num_ev);
   svm_msg_q_unlock (mq);
 
 handle_dequeued:
@@ -2487,10 +2488,7 @@ handle_dequeued:
     {
       msg = vec_elt_at_index (wrk->mq_msg_vector, i);
       e = svm_msg_q_msg_data (mq, msg);
-      if (*num_ev < maxevents)
-	vcl_epoll_wait_handle_mq_event (wrk, e, events, num_ev);
-      else
-	vec_add1 (wrk->unhandled_evts_vector, *e);
+      vcl_epoll_wait_handle_mq_event (wrk, e, events, num_ev);
       svm_msg_q_free_msg (mq, msg);
     }
   vec_reset_length (wrk->mq_msg_vector);
@@ -2502,7 +2500,7 @@ static int
 vppcom_epoll_wait_condvar (vcl_worker_t * wrk, struct epoll_event *events,
 			   int maxevents, u32 n_evts, double wait_for_time)
 {
-  double wait = 0, start = 0;
+  double wait = 0, start = 0, now;
 
   if (!n_evts)
     {
@@ -2519,7 +2517,9 @@ vppcom_epoll_wait_condvar (vcl_worker_t * wrk, struct epoll_event *events,
       if (wait == -1)
 	continue;
 
-      wait = wait - (clib_time_now (&wrk->clib_time) - start);
+      now = clib_time_now (&wrk->clib_time);
+      wait -= now - start;
+      start = now;
     }
   while (wait > 0);
 
@@ -2586,11 +2586,11 @@ vppcom_epoll_wait (uint32_t vep_handle, struct epoll_event *events,
 					  events, &n_evts);
 	  if (n_evts == maxevents)
 	    {
-	      i += 1;
-	      break;
+	      vec_delete (wrk->unhandled_evts_vector, i + 1, 0);
+	      return n_evts;
 	    }
 	}
-      vec_delete (wrk->unhandled_evts_vector, i, 0);
+      vec_reset_length (wrk->unhandled_evts_vector);
     }
 
   if (vcm->cfg.use_mq_eventfd)