session: move connects to first worker

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I035e3fdbb52eca010ad7b2c20ca2930cb1645978

1 files changed, 13 insertions, 19 deletions

diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index 16000e62fa8..b8cc1c383c9 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -157,9 +157,6 @@ typedef struct session_worker_
   /** Flag that is set if main thread signaled to handle connects */
   u32 n_pending_connects;
 
-  /** Main thread loops in poll mode without a connect */
-  u32 no_connect_loops;
-
   /** List head for first worker evts pending handling on main */
   clib_llist_index_t evts_pending_main;
 
@@ -212,7 +209,9 @@ typedef struct session_main_
    * Trade memory for speed, for now */
   u32 *session_type_to_next;
 
-  /** Thread for cl and ho that rely on cl allocs */
+  /** Thread used for allocating active open connections, i.e., half-opens
+   * for transports like tcp, and sessions that will be migrated for cl
+   * transports like udp. If vpp has workers, this will be first worker. */
   u32 transport_cl_thread;
 
   transport_proto_t last_transport_proto_type;
@@ -616,6 +615,13 @@ transport_cl_thread (void)
   return session_main.transport_cl_thread;
 }
 
+always_inline u32
+session_vlib_thread_is_cl_thread (void)
+{
+  return (vlib_get_thread_index () == transport_cl_thread () ||
+	  vlib_thread_is_main_w_barrier ());
+}
+
 /*
  * Listen sessions
  */
@@ -668,29 +674,17 @@ always_inline session_t *
 ho_session_alloc (void)
 {
   session_t *s;
-  ASSERT (vlib_get_thread_index () == 0);
-  s = session_alloc (0);
+  ASSERT (session_vlib_thread_is_cl_thread ());
+  s = session_alloc (transport_cl_thread ());
   s->session_state = SESSION_STATE_CONNECTING;
   s->flags |= SESSION_F_HALF_OPEN;
-  /* Not ideal. Half-opens are only allocated from main with worker barrier
-   * but can be cleaned up, i.e., session_half_open_free, from main without
-   * a barrier. In debug images, the free_bitmap can grow while workers peek
-   * the sessions pool, e.g., session_half_open_migrate_notify, and as a
-   * result crash while validating the session. To avoid this, grow the bitmap
-   * now. */
-  if (CLIB_DEBUG)
-    {
-      session_t *sp = session_main.wrk[0].sessions;
-      clib_bitmap_validate (pool_header (sp)->free_bitmap,
-			    s->session_index + 1);
-    }
   return s;
 }
 
 always_inline session_t *
 ho_session_get (u32 ho_index)
 {
-  return session_get (ho_index, 0 /* half-open thread */);
+  return session_get (ho_index, transport_cl_thread ());
 }
 
 always_inline void