X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvnet%2Fsession%2Fsegment_manager.c;h=ad0ba89a1dd7b17f081cdd0717743db3866b22e7;hb=ac3c8dcb076245544e61dabb984d057167572276;hp=bb3d7adc379771d37e2b7449c9f3078e66294eb1;hpb=213b1bb3b9652ce2937e3b47573cc54ee3008387;p=vpp.git

diff --git a/src/vnet/session/segment_manager.c b/src/vnet/session/segment_manager.c
index bb3d7adc379..ad0ba89a1dd 100644
--- a/src/vnet/session/segment_manager.c
+++ b/src/vnet/session/segment_manager.c
@@ -20,7 +20,6 @@
 typedef struct segment_manager_main_
 {
   segment_manager_t *segment_managers;	/**< Pool of segment managers */
-  clib_valloc_main_t va_allocator;	/**< Virtual address allocator */
   u32 seg_name_counter;			/**< Counter for segment names */
 
   /*
@@ -88,30 +87,32 @@ segment_manager_segment_index (segment_manager_t * sm, fifo_segment_t * seg)
  * If needed a writer's lock is acquired before allocating a new segment
  * to avoid affecting any of the segments pool readers.
  */
-int
-segment_manager_add_segment (segment_manager_t * sm, uword segment_size)
+static inline int
+segment_manager_add_segment_inline (segment_manager_t *sm, uword segment_size,
+				    u8 notify_app, u8 flags, u8 need_lock)
 {
-  uword baseva = (uword) ~ 0ULL, alloc_size, page_size;
-  u32 rnd_margin = 128 << 10, fs_index = ~0;
   segment_manager_main_t *smm = &sm_main;
   segment_manager_props_t *props;
+  app_worker_t *app_wrk;
   fifo_segment_t *fs;
+  u32 fs_index = ~0;
   u8 *seg_name;
   int rv;
 
   props = segment_manager_properties_get (sm);
+  app_wrk = app_worker_get (sm->app_wrk_index);
 
   /* Not configured for addition of new segments and not first */
   if (!props->add_segment && !segment_size)
     {
-      clib_warning ("cannot allocate new segment");
-      return VNET_API_ERROR_INVALID_VALUE;
+      SESSION_DBG ("cannot allocate new segment");
+      return SESSION_E_INVALID;
     }
 
   /*
    * Allocate fifo segment and grab lock if needed
    */
-  if (vlib_num_workers ())
+  if (need_lock)
     clib_rwlock_writer_lock (&sm->segments_rwlock);
 
   pool_get_zero (sm->segments, fs);
@@ -120,42 +121,33 @@ segment_manager_add_segment (segment_manager_t * sm, uword segment_size)
    * Allocate ssvm segment
    */
   segment_size = segment_size ? segment_size : props->add_segment_size;
-  page_size = clib_mem_get_page_size ();
-  /* Protect against segment size u32 wrap */
-  segment_size = clib_max (segment_size + page_size - 1, segment_size);
-  segment_size = segment_size & ~(page_size - 1);
-
-  if (props->segment_type != SSVM_SEGMENT_PRIVATE)
+  /* add overhead to ensure the result segment size is at least
+   * of that requested */
+  segment_size +=
+    sizeof (fifo_segment_header_t) +
+    vlib_thread_main.n_vlib_mains * sizeof (fifo_segment_slice_t) +
+    FIFO_SEGMENT_ALLOC_OVERHEAD;
+
+  if (props->huge_page)
     {
-      seg_name = format (0, "%d-%d%c", getpid (), smm->seg_name_counter++, 0);
-      alloc_size = (uword) segment_size + rnd_margin;
-      baseva = clib_valloc_alloc (&smm->va_allocator, alloc_size, 0);
-      if (!baseva)
-	{
-	  clib_warning ("out of space for segments");
-	  pool_put (sm->segments, fs);
-	  goto done;
-	}
+      uword hugepage_size = clib_mem_get_default_hugepage_size ();
+      segment_size = round_pow2 (segment_size, hugepage_size);
+      fs->ssvm.huge_page = 1;
     }
   else
-    {
-      app_worker_t *app_wrk = app_worker_get (sm->app_wrk_index);
-      application_t *app = application_get (app_wrk->app_index);
-      seg_name = format (0, "%v segment%c", app->name, 0);
-    }
+    segment_size = round_pow2 (segment_size, clib_mem_get_page_size ());
+
+  seg_name = format (0, "seg-%u-%u-%u%c", app_wrk->app_index,
+		     app_wrk->wrk_index, smm->seg_name_counter++, 0);
 
   fs->ssvm.ssvm_size = segment_size;
   fs->ssvm.name = seg_name;
-  /* clib_mem_vm_map_shared consumes first page before requested_va */
-  fs->ssvm.requested_va = baseva + page_size;
+  fs->ssvm.requested_va = 0;
 
   if ((rv = ssvm_server_init (&fs->ssvm, props->segment_type)))
     {
       clib_warning ("svm_master_init ('%v', %u) failed", seg_name,
 		    segment_size);
-
-      if (props->segment_type != SSVM_SEGMENT_PRIVATE)
-	clib_valloc_free (&smm->va_allocator, baseva);
       pool_put (sm->segments, fs);
       goto done;
     }
@@ -170,37 +162,63 @@ segment_manager_add_segment (segment_manager_t * sm, uword segment_size)
    * Save segment index before dropping lock, if any held
    */
   fs_index = fs - sm->segments;
+  fs->fs_index = fs_index;
+  fs->sm_index = segment_manager_index (sm);
 
   /*
    * Set watermarks in segment
    */
-  fs->h->high_watermark = sm->high_watermark;
-  fs->h->low_watermark = sm->low_watermark;
+  fs->high_watermark = sm->high_watermark;
+  fs->low_watermark = sm->low_watermark;
+  fs->flags = flags;
+  fs->flags &= ~FIFO_SEGMENT_F_MEM_LIMIT;
   fs->h->pct_first_alloc = props->pct_first_alloc;
-  fs->h->flags &= ~FIFO_SEGMENT_F_MEM_LIMIT;
 
+  if (notify_app)
+    {
+      app_worker_t *app_wrk;
+      u64 fs_handle;
+      fs_handle = segment_manager_segment_handle (sm, fs);
+      app_wrk = app_worker_get (sm->app_wrk_index);
+      rv = app_worker_add_segment_notify (app_wrk, fs_handle);
+      if (rv)
+	{
+	  fs_index = rv;
+	  goto done;
+	}
+    }
 done:
 
-  if (vlib_num_workers ())
+  if (need_lock)
     clib_rwlock_writer_unlock (&sm->segments_rwlock);
 
   return fs_index;
 }
 
+int
+segment_manager_add_segment (segment_manager_t *sm, uword segment_size,
+			     u8 notify_app)
+{
+  return segment_manager_add_segment_inline (sm, segment_size, notify_app,
+					     0 /* flags */, 0 /* need_lock */);
+}
+
+int
+segment_manager_add_segment2 (segment_manager_t *sm, uword segment_size,
+			      u8 flags)
+{
+  return segment_manager_add_segment_inline (sm, segment_size, 0, flags,
+					     vlib_num_workers ());
+}
+
 /**
  * Remove segment without lock
  */
 void
 segment_manager_del_segment (segment_manager_t * sm, fifo_segment_t * fs)
 {
-  segment_manager_main_t *smm = &sm_main;
-
   if (ssvm_type (&fs->ssvm) != SSVM_SEGMENT_PRIVATE)
     {
-      /* clib_mem_vm_map_shared consumes first page before requested_va */
-      clib_valloc_free (&smm->va_allocator,
-			fs->ssvm.requested_va - clib_mem_get_page_size ());
-
       if (!segment_manager_app_detached (sm))
 	{
 	  app_worker_t *app_wrk;
@@ -211,6 +229,7 @@ segment_manager_del_segment (segment_manager_t * sm, fifo_segment_t * fs)
 	}
     }
 
+  fifo_segment_cleanup (fs);
   ssvm_delete (&fs->ssvm);
 
   if (CLIB_DEBUG)
@@ -231,7 +250,8 @@ segment_manager_get_segment_if_valid (segment_manager_t * sm,
  * Removes segment after acquiring writer lock
  */
 static inline void
-sm_lock_and_del_segment_inline (segment_manager_t * sm, u32 fs_index)
+sm_lock_and_del_segment_inline (segment_manager_t *sm, u32 fs_index,
+				u8 check_if_empty)
 {
   fifo_segment_t *fs;
   u8 is_prealloc;
@@ -242,6 +262,9 @@ sm_lock_and_del_segment_inline (segment_manager_t * sm, u32 fs_index)
   if (!fs)
     goto done;
 
+  if (check_if_empty && fifo_segment_has_fifos (fs))
+    goto done;
+
   is_prealloc = fifo_segment_flags (fs) & FIFO_SEGMENT_F_IS_PREALLOCATED;
   if (is_prealloc && !segment_manager_app_detached (sm))
     goto done;
@@ -255,7 +278,7 @@ done:
 void
 segment_manager_lock_and_del_segment (segment_manager_t * sm, u32 fs_index)
 {
-  sm_lock_and_del_segment_inline (sm, fs_index);
+  sm_lock_and_del_segment_inline (sm, fs_index, 0 /* check_if_empty */);
 }
 
 /**
@@ -322,12 +345,6 @@ segment_manager_segment_reader_unlock (segment_manager_t * sm)
   clib_rwlock_reader_unlock (&sm->segments_rwlock);
 }
 
-void
-segment_manager_segment_writer_unlock (segment_manager_t * sm)
-{
-  clib_rwlock_writer_unlock (&sm->segments_rwlock);
-}
-
 segment_manager_t *
 segment_manager_alloc (void)
 {
@@ -398,10 +415,10 @@ segment_manager_init_first (segment_manager_t * sm)
       /* Allocate the segments */
       for (i = 0; i < approx_segment_count + 1; i++)
 	{
-	  fs_index = segment_manager_add_segment (sm, max_seg_size);
+	  fs_index = segment_manager_add_segment (sm, max_seg_size, 0);
 	  if (fs_index < 0)
 	    {
-	      clib_warning ("Failed to preallocate segment %d", i);
+	      SESSION_DBG ("Failed to preallocate segment %d", i);
 	      return fs_index;
 	    }
 
@@ -420,10 +437,10 @@ segment_manager_init_first (segment_manager_t * sm)
       return 0;
     }
 
-  fs_index = segment_manager_add_segment (sm, first_seg_size);
+  fs_index = segment_manager_add_segment (sm, first_seg_size, 0);
   if (fs_index < 0)
     {
-      clib_warning ("Failed to allocate segment");
+      SESSION_DBG ("Failed to allocate segment");
       return fs_index;
     }
 
@@ -441,7 +458,7 @@ segment_manager_init_first (segment_manager_t * sm)
       for (; i < fs->n_slices; i++)
 	{
 	  if (fifo_segment_prealloc_fifo_hdrs (fs, i, hdrs_per_slice))
-	    return VNET_API_ERROR_SVM_SEGMENT_CREATE_FAIL;
+	    return SESSION_E_SEG_CREATE;
 	}
     }
 
@@ -488,6 +505,7 @@ segment_manager_free (segment_manager_t * sm)
   }
   /* *INDENT-ON* */
 
+  pool_free (sm->segments);
   clib_rwlock_writer_unlock (&sm->segments_rwlock);
 
   clib_rwlock_free (&sm->segments_rwlock);
@@ -508,8 +526,8 @@ sm_free_w_index_helper (void *arg)
     segment_manager_free (sm);
 }
 
-static void
-segment_manager_free_safe (segment_manager_t * sm)
+void
+segment_manager_free_safe (segment_manager_t *sm)
 {
   if (!vlib_thread_is_main_w_barrier ())
     {
@@ -612,12 +630,12 @@ segment_manager_del_sessions (segment_manager_t * sm)
          */
         while (f)
           {
-            session = session_get_if_valid (f->master_session_index,
-                                            f->master_thread_index);
-            if (session)
-              vec_add1 (handles, session_handle (session));
-            f = f->next;
-          }
+	    session = session_get_if_valid (f->shr->master_session_index,
+					    f->master_thread_index);
+	    if (session)
+	      vec_add1 (handles, session_handle (session));
+	    f = f->next;
+	  }
       }
 
     /* Instead of removing the segment, test when cleaning up disconnected
@@ -633,22 +651,73 @@ segment_manager_del_sessions (segment_manager_t * sm)
     /* Avoid propagating notifications back to the app */
     session->app_wrk_index = APP_INVALID_INDEX;
   }
+  vec_free (handles);
+}
+
+/**
+ * Initiate disconnects for sessions in specified state 'owned' by a segment
+ * manager
+ */
+void
+segment_manager_del_sessions_filter (segment_manager_t *sm,
+				     session_state_t *states)
+{
+  session_handle_t *handles = 0, *handle;
+  fifo_segment_t *fs;
+  session_t *session;
+  int slice_index;
+  svm_fifo_t *f;
+
+  ASSERT (pool_elts (sm->segments) != 0);
+
+  /* Across all fifo segments used by the server */
+  segment_manager_foreach_segment_w_lock (
+    fs, sm, ({
+      for (slice_index = 0; slice_index < fs->n_slices; slice_index++)
+	{
+	  f = fifo_segment_get_slice_fifo_list (fs, slice_index);
+	  while (f)
+	    {
+	      session = session_get_if_valid (f->shr->master_session_index,
+					      f->master_thread_index);
+	      if (session)
+		{
+		  session_state_t *state;
+		  vec_foreach (state, states)
+		    {
+		      if (session->session_state == *state)
+			{
+			  vec_add1 (handles, session_handle (session));
+			  break;
+			}
+		    }
+		}
+	      f = f->next;
+	    }
+	}
+    }));
+
+  vec_foreach (handle, handles)
+    {
+      session = session_get_from_handle (*handle);
+      session_close (session);
+      /* Avoid propagating notifications back to the app */
+      session->app_wrk_index = APP_INVALID_INDEX;
+    }
+  vec_free (handles);
 }
 
 int
-segment_manager_try_alloc_fifos (fifo_segment_t * fifo_segment,
-				 u32 thread_index,
+segment_manager_try_alloc_fifos (fifo_segment_t *fs, u32 thread_index,
 				 u32 rx_fifo_size, u32 tx_fifo_size,
-				 svm_fifo_t ** rx_fifo, svm_fifo_t ** tx_fifo)
+				 svm_fifo_t **rx_fifo, svm_fifo_t **tx_fifo)
 {
   rx_fifo_size = clib_max (rx_fifo_size, sm_main.default_fifo_size);
-  *rx_fifo = fifo_segment_alloc_fifo_w_slice (fifo_segment, thread_index,
-					      rx_fifo_size,
+  *rx_fifo = fifo_segment_alloc_fifo_w_slice (fs, thread_index, rx_fifo_size,
 					      FIFO_SEGMENT_RX_FIFO);
 
   tx_fifo_size = clib_max (tx_fifo_size, sm_main.default_fifo_size);
-  *tx_fifo = fifo_segment_alloc_fifo_w_slice (fifo_segment, thread_index,
-					      tx_fifo_size,
+  *tx_fifo = fifo_segment_alloc_fifo_w_slice (fs, thread_index, tx_fifo_size,
 					      FIFO_SEGMENT_TX_FIFO);
 
   if (*rx_fifo == 0)
@@ -656,126 +725,132 @@ segment_manager_try_alloc_fifos (fifo_segment_t * fifo_segment,
       /* This would be very odd, but handle it... */
       if (*tx_fifo != 0)
 	{
-	  fifo_segment_free_fifo (fifo_segment, *tx_fifo);
+	  fifo_segment_free_fifo (fs, *tx_fifo);
 	  *tx_fifo = 0;
 	}
-      return -1;
+      return SESSION_E_SEG_NO_SPACE;
     }
   if (*tx_fifo == 0)
     {
       if (*rx_fifo != 0)
 	{
-	  fifo_segment_free_fifo (fifo_segment, *rx_fifo);
+	  fifo_segment_free_fifo (fs, *rx_fifo);
 	  *rx_fifo = 0;
 	}
-      return -1;
+      return SESSION_E_SEG_NO_SPACE;
     }
 
   return 0;
 }
 
+static inline int
+sm_lookup_segment_and_alloc_fifos (segment_manager_t *sm,
+				   segment_manager_props_t *props,
+				   u32 thread_index, svm_fifo_t **rx_fifo,
+				   svm_fifo_t **tx_fifo)
+{
+  uword free_bytes, max_free_bytes;
+  fifo_segment_t *cur, *fs = 0;
+
+  max_free_bytes = props->rx_fifo_size + props->tx_fifo_size - 1;
+
+  pool_foreach (cur, sm->segments)
+    {
+      if (fifo_segment_flags (cur) & FIFO_SEGMENT_F_CUSTOM_USE)
+	continue;
+      free_bytes = fifo_segment_available_bytes (cur);
+      if (free_bytes > max_free_bytes)
+	{
+	  max_free_bytes = free_bytes;
+	  fs = cur;
+	}
+    }
+
+  if (PREDICT_FALSE (!fs))
+    return SESSION_E_SEG_NO_SPACE;
+
+  return segment_manager_try_alloc_fifos (
+    fs, thread_index, props->rx_fifo_size, props->tx_fifo_size, rx_fifo,
+    tx_fifo);
+}
+
+static int
+sm_lock_and_alloc_segment_and_fifos (segment_manager_t *sm,
+				     segment_manager_props_t *props,
+				     u32 thread_index, svm_fifo_t **rx_fifo,
+				     svm_fifo_t **tx_fifo)
+{
+  int new_fs_index, rv;
+  fifo_segment_t *fs;
+
+  if (!props->add_segment)
+    return SESSION_E_SEG_NO_SPACE;
+
+  clib_rwlock_writer_lock (&sm->segments_rwlock);
+
+  /* Make sure there really is no free space. Another worker might've freed
+   * some fifos or allocated a segment */
+  rv = sm_lookup_segment_and_alloc_fifos (sm, props, thread_index, rx_fifo,
+					  tx_fifo);
+  if (!rv)
+    goto done;
+
+  new_fs_index =
+    segment_manager_add_segment (sm, 0 /* segment_size*/, 1 /* notify_app */);
+  if (new_fs_index < 0)
+    {
+      rv = SESSION_E_SEG_CREATE;
+      goto done;
+    }
+  fs = segment_manager_get_segment (sm, new_fs_index);
+  rv = segment_manager_try_alloc_fifos (fs, thread_index, props->rx_fifo_size,
+					props->tx_fifo_size, rx_fifo, tx_fifo);
+  if (rv)
+    {
+      SESSION_DBG ("Added a segment, still can't allocate a fifo");
+      rv = SESSION_E_SEG_NO_SPACE2;
+      goto done;
+    }
+
+done:
+
+  clib_rwlock_writer_unlock (&sm->segments_rwlock);
+
+  return rv;
+}
+
 int
 segment_manager_alloc_session_fifos (segment_manager_t * sm,
 				     u32 thread_index,
 				     svm_fifo_t ** rx_fifo,
 				     svm_fifo_t ** tx_fifo)
 {
-  int alloc_fail = 1, rv = 0, new_fs_index;
-  uword free_bytes, max_free_bytes = 0;
   segment_manager_props_t *props;
-  fifo_segment_t *fs = 0, *cur;
-  u32 sm_index, fs_index;
-  u8 added_a_segment = 0;
-  u64 fs_handle;
+  int rv;
 
   props = segment_manager_properties_get (sm);
 
   /*
-   * Find the first free segment to allocate the fifos in
+   * Fast path: find the first segment with enough free space and
+   * try to allocate the fifos. Done with reader lock
    */
 
   segment_manager_segment_reader_lock (sm);
 
-  /* *INDENT-OFF* */
-  pool_foreach (cur, sm->segments)  {
-    free_bytes = fifo_segment_available_bytes (cur);
-    if (free_bytes > max_free_bytes)
-      {
-        max_free_bytes = free_bytes;
-        fs = cur;
-      }
-  }
-  /* *INDENT-ON* */
-
-  if (fs)
-    {
-      alloc_fail = segment_manager_try_alloc_fifos (fs, thread_index,
-						    props->rx_fifo_size,
-						    props->tx_fifo_size,
-						    rx_fifo, tx_fifo);
-      /* On success, keep lock until fifos are initialized */
-      if (!alloc_fail)
-	goto alloc_success;
-    }
+  rv = sm_lookup_segment_and_alloc_fifos (sm, props, thread_index, rx_fifo,
+					  tx_fifo);
 
   segment_manager_segment_reader_unlock (sm);
 
-alloc_check:
-
-  if (!alloc_fail)
-    {
-
-    alloc_success:
-
-      ASSERT (rx_fifo && tx_fifo);
-      sm_index = segment_manager_index (sm);
-      fs_index = segment_manager_segment_index (sm, fs);
-      (*tx_fifo)->segment_manager = sm_index;
-      (*rx_fifo)->segment_manager = sm_index;
-      (*tx_fifo)->segment_index = fs_index;
-      (*rx_fifo)->segment_index = fs_index;
-
-      if (added_a_segment)
-	{
-	  app_worker_t *app_wrk;
-	  fs_handle = segment_manager_segment_handle (sm, fs);
-	  app_wrk = app_worker_get (sm->app_wrk_index);
-	  rv = app_worker_add_segment_notify (app_wrk, fs_handle);
-	}
-      /* Drop the lock after app is notified */
-      segment_manager_segment_reader_unlock (sm);
-      return rv;
-    }
-
   /*
-   * Allocation failed, see if we can add a new segment
+   * Slow path: if no fifo segment or alloc fail grab writer lock and try
+   * to allocate new segment
    */
-  if (props->add_segment)
-    {
-      if (added_a_segment)
-	{
-	  clib_warning ("Added a segment, still can't allocate a fifo");
-	  segment_manager_segment_reader_unlock (sm);
-	  return SESSION_E_SEG_NO_SPACE2;
-	}
-      if ((new_fs_index = segment_manager_add_segment (sm, 0)) < 0)
-	{
-	  clib_warning ("Failed to add new segment");
-	  return SESSION_E_SEG_CREATE;
-	}
-      fs = segment_manager_get_segment_w_lock (sm, new_fs_index);
-      alloc_fail = segment_manager_try_alloc_fifos (fs, thread_index,
-						    props->rx_fifo_size,
-						    props->tx_fifo_size,
-						    rx_fifo, tx_fifo);
-      added_a_segment = 1;
-      goto alloc_check;
-    }
-  else
-    {
-      SESSION_DBG ("Can't add new seg and no space to allocate fifos!");
-      return SESSION_E_SEG_NO_SPACE;
-    }
+  if (PREDICT_FALSE (rv < 0))
+    return sm_lock_and_alloc_segment_and_fifos (sm, props, thread_index,
+						rx_fifo, tx_fifo);
+
+  return 0;
 }
 
 void
@@ -784,10 +859,15 @@ segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo, svm_fifo_t * tx_fifo)
   segment_manager_t *sm;
   fifo_segment_t *fs;
   u32 segment_index;
+  u8 try_delete = 0;
 
   if (!rx_fifo || !tx_fifo)
     return;
 
+  /* Thread that allocated the fifos must be the one to clean them up */
+  ASSERT (rx_fifo->master_thread_index == vlib_get_thread_index () ||
+	  rx_fifo->refcnt > 1);
+
   /* It's possible to have no segment manager if the session was removed
    * as result of a detach. */
   if (!(sm = segment_manager_get_if_valid (rx_fifo->segment_manager)))
@@ -799,50 +879,54 @@ segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo, svm_fifo_t * tx_fifo)
   fifo_segment_free_fifo (fs, tx_fifo);
 
   /*
-   * Try to remove svm segment if it has no fifos. This can be done only if
+   * Try to remove fifo segment if it has no fifos. This can be done only if
    * the segment is not the first in the segment manager or if it is first
    * and it is not protected. Moreover, if the segment is first and the app
    * has detached from the segment manager, remove the segment manager.
    */
   if (!fifo_segment_has_fifos (fs))
     {
-      segment_manager_segment_reader_unlock (sm);
+      /* If first, remove only if not protected */
+      try_delete = segment_index != 0 || !sm->first_is_protected;
+    }
 
-      /* Remove segment if it holds no fifos or first but not protected */
-      if (segment_index != 0 || !sm->first_is_protected)
-	sm_lock_and_del_segment_inline (sm, segment_index);
+  segment_manager_segment_reader_unlock (sm);
+
+  if (PREDICT_FALSE (try_delete))
+    {
+      /* Only remove if empty after writer lock acquired */
+      sm_lock_and_del_segment_inline (sm, segment_index,
+				      1 /* check_if_empty */);
 
       /* Remove segment manager if no sessions and detached from app */
       if (segment_manager_app_detached (sm)
 	  && !segment_manager_has_fifos (sm))
 	segment_manager_free_safe (sm);
     }
-  else
-    segment_manager_segment_reader_unlock (sm);
 }
 
 void
-segment_manager_detach_fifo (segment_manager_t * sm, svm_fifo_t * f)
+segment_manager_detach_fifo (segment_manager_t *sm, svm_fifo_t **f)
 {
   fifo_segment_t *fs;
 
-  fs = segment_manager_get_segment_w_lock (sm, f->segment_index);
+  fs = segment_manager_get_segment_w_lock (sm, (*f)->segment_index);
   fifo_segment_detach_fifo (fs, f);
   segment_manager_segment_reader_unlock (sm);
 }
 
 void
-segment_manager_attach_fifo (segment_manager_t * sm, svm_fifo_t * f,
-			     session_t * s)
+segment_manager_attach_fifo (segment_manager_t *sm, svm_fifo_t **f,
+			     session_t *s)
 {
   fifo_segment_t *fs;
 
-  fs = segment_manager_get_segment_w_lock (sm, f->segment_index);
+  fs = segment_manager_get_segment_w_lock (sm, (*f)->segment_index);
   fifo_segment_attach_fifo (fs, f, s->thread_index);
   segment_manager_segment_reader_unlock (sm);
 
-  f->master_session_index = s->session_index;
-  f->master_thread_index = s->thread_index;
+  (*f)->shr->master_session_index = s->session_index;
+  (*f)->master_thread_index = s->thread_index;
 }
 
 u32
@@ -874,7 +958,6 @@ segment_manager_alloc_queue (fifo_segment_t * segment,
   u32 fifo_evt_size, session_evt_size = 256, notif_q_size;
   svm_msg_q_cfg_t _cfg, *cfg = &_cfg;
   svm_msg_q_t *q;
-  void *base;
 
   fifo_evt_size = sizeof (session_event_t);
   notif_q_size = clib_max (16, props->evt_q_size >> 4);
@@ -889,12 +972,11 @@ segment_manager_alloc_queue (fifo_segment_t * segment,
   cfg->q_nitems = props->evt_q_size;
   cfg->ring_cfgs = rc;
 
-  base = fifo_segment_alloc (segment, svm_msg_q_size_to_alloc (cfg));
-  q = svm_msg_q_init (base, cfg);
+  q = fifo_segment_msg_q_alloc (segment, 0, cfg);
 
   if (props->use_mq_eventfd)
     {
-      if (svm_msg_q_alloc_producer_eventfd (q))
+      if (svm_msg_q_alloc_eventfd (q))
 	clib_warning ("failed to alloc eventfd");
     }
   return q;
@@ -931,15 +1013,9 @@ segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q)
  * Init segment vm address allocator
  */
 void
-segment_manager_main_init (segment_manager_main_init_args_t * a)
+segment_manager_main_init (void)
 {
   segment_manager_main_t *sm = &sm_main;
-  clib_valloc_chunk_t _ip, *ip = &_ip;
-
-  ip->baseva = a->baseva;
-  ip->size = a->size;
-
-  clib_valloc_init (&sm->va_allocator, ip, 1 /* lock */ );
 
   sm->default_fifo_size = 1 << 12;
   sm->default_segment_size = 1 << 20;
@@ -949,76 +1025,110 @@ segment_manager_main_init (segment_manager_main_init_args_t * a)
   sm->default_low_watermark = 50;
 }
 
+static u8 *
+format_segment_manager (u8 *s, va_list *args)
+{
+  segment_manager_t *sm = va_arg (*args, segment_manager_t *);
+  int verbose = va_arg (*args, int);
+  app_worker_t *app_wrk;
+  uword max_fifo_size;
+  fifo_segment_t *seg;
+  application_t *app;
+  u8 custom_logic;
+
+  app_wrk = app_worker_get_if_valid (sm->app_wrk_index);
+  app = app_wrk ? application_get (app_wrk->app_index) : 0;
+  custom_logic = (app && (app->cb_fns.fifo_tuning_callback)) ? 1 : 0;
+  max_fifo_size = sm->max_fifo_size;
+
+  s = format (s,
+	      "[%u] %v app-wrk: %u segs: %u max-fifo-sz: %U "
+	      "wmarks: %u %u %s flags: 0x%x",
+	      segment_manager_index (sm), app ? app->name : 0,
+	      sm->app_wrk_index, pool_elts (sm->segments), format_memory_size,
+	      max_fifo_size, sm->high_watermark, sm->low_watermark,
+	      custom_logic ? "custom-tuning" : "no-tuning", sm->flags);
+
+  if (!verbose || !pool_elts (sm->segments))
+    return s;
+
+  s = format (s, "\n\n");
+
+  segment_manager_foreach_segment_w_lock (
+    seg, sm, ({ s = format (s, " *%U", format_fifo_segment, seg, verbose); }));
+
+  return s;
+}
+
 static clib_error_t *
 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 			 vlib_cli_command_t * cmd)
 {
+  unformat_input_t _line_input, *line_input = &_line_input;
   segment_manager_main_t *smm = &sm_main;
   u8 show_segments = 0, verbose = 0;
-  uword max_fifo_size;
   segment_manager_t *sm;
-  fifo_segment_t *seg;
-  app_worker_t *app_wrk;
-  application_t *app;
-  u8 custom_logic;
+  u32 sm_index = ~0;
+
+  if (!unformat_user (input, unformat_line_input, line_input))
+    {
+      vlib_cli_output (vm, "%d segment managers allocated",
+		       pool_elts (smm->segment_managers));
+      return 0;
+    }
 
-  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
     {
-      if (unformat (input, "segments"))
+      if (unformat (line_input, "segments"))
 	show_segments = 1;
-      else if (unformat (input, "verbose"))
+      else if (unformat (line_input, "verbose"))
 	verbose = 1;
+      else if (unformat (line_input, "index %u", &sm_index))
+	;
       else
-	return clib_error_return (0, "unknown input `%U'",
-				  format_unformat_error, input);
+	{
+	  vlib_cli_output (vm, "unknown input [%U]", format_unformat_error,
+			   line_input);
+	  goto done;
+	}
     }
-  vlib_cli_output (vm, "%d segment managers allocated",
-		   pool_elts (smm->segment_managers));
-  if (verbose && pool_elts (smm->segment_managers))
+
+  if (!pool_elts (smm->segment_managers))
+    goto done;
+
+  if (sm_index != ~0)
     {
-      vlib_cli_output (vm, "%-6s%=10s%=10s%=13s%=11s%=11s%=12s",
-		       "Index", "AppIndex", "Segments", "MaxFifoSize",
-		       "HighWater", "LowWater", "FifoTuning");
+      sm = segment_manager_get_if_valid (sm_index);
+      if (!sm)
+	{
+	  vlib_cli_output (vm, "segment manager %u not allocated", sm_index);
+	  goto done;
+	}
+      vlib_cli_output (vm, "%U", format_segment_manager, sm, 1 /* verbose */);
+      goto done;
+    }
 
-      /* *INDENT-OFF* */
+  if (verbose || show_segments)
+    {
       pool_foreach (sm, smm->segment_managers)  {
-        app_wrk = app_worker_get_if_valid (sm->app_wrk_index);
-        app = app_wrk ? application_get (app_wrk->app_index) : 0;
-        custom_logic = (app && (app->cb_fns.fifo_tuning_callback)) ? 1 : 0;
-        max_fifo_size = sm->max_fifo_size;
-
-	vlib_cli_output (vm, "%-6d%=10d%=10d%=13U%=11d%=11d%=12s",
-                         segment_manager_index (sm),
-			 sm->app_wrk_index, pool_elts (sm->segments),
-                         format_memory_size, max_fifo_size,
-                         sm->high_watermark, sm->low_watermark,
-                         custom_logic ? "custom" : "none");
+	  vlib_cli_output (vm, "%U", format_segment_manager, sm,
+			   show_segments);
       }
-      /* *INDENT-ON* */
 
       vlib_cli_output (vm, "\n");
     }
-  if (show_segments)
-    {
-      vlib_cli_output (vm, "%U", format_fifo_segment, 0, verbose);
 
-      /* *INDENT-OFF* */
-      pool_foreach (sm, smm->segment_managers)  {
-	  segment_manager_foreach_segment_w_lock (seg, sm, ({
-	    vlib_cli_output (vm, "%U", format_fifo_segment, seg, verbose);
-	  }));
-      }
-      /* *INDENT-ON* */
+done:
+
+  unformat_free (line_input);
 
-    }
   return 0;
 }
 
 /* *INDENT-OFF* */
-VLIB_CLI_COMMAND (segment_manager_show_command, static) =
-{
+VLIB_CLI_COMMAND (segment_manager_show_command, static) = {
   .path = "show segment-manager",
-  .short_help = "show segment-manager [segments][verbose]",
+  .short_help = "show segment-manager [segments][verbose][index <nn>]",
   .function = segment_manager_show_fn,
 };
 /* *INDENT-ON* */
@@ -1037,10 +1147,11 @@ segment_manager_format_sessions (segment_manager_t * sm, int verbose)
   if (!sm)
     {
       if (verbose)
-	vlib_cli_output (vm, "%-40s%-20s%-15s%-10s", "Connection", "App",
-			 "API Client", "SegManager");
+	vlib_cli_output (vm, "%-" SESSION_CLI_ID_LEN "s%-20s%-15s%-10s",
+			 "Connection", "App", "API Client", "SegManager");
       else
-	vlib_cli_output (vm, "%-40s%-20s", "Connection", "App");
+	vlib_cli_output (vm, "%-" SESSION_CLI_ID_LEN "s%-20s", "Connection",
+			 "App");
       return;
     }
 
@@ -1059,25 +1170,26 @@ segment_manager_format_sessions (segment_manager_t * sm, int verbose)
             u32 session_index, thread_index;
             session_t *session;
 
-            session_index = f->master_session_index;
-            thread_index = f->master_thread_index;
+	    session_index = f->shr->master_session_index;
+	    thread_index = f->master_thread_index;
 
-            session = session_get (session_index, thread_index);
-            str = format (0, "%U", format_session, session, verbose);
+	    session = session_get (session_index, thread_index);
+	    str = format (0, "%U", format_session, session, verbose);
 
-            if (verbose)
-              s = format (s, "%-40v%-20v%-15u%-10u", str, app_name,
-                          app_wrk->api_client_index, app_wrk->connects_seg_manager);
-            else
-              s = format (s, "%-40v%-20v", str, app_name);
+	    if (verbose)
+	      s = format (s, "%-" SESSION_CLI_ID_LEN "v%-20v%-15u%-10u", str,
+			  app_name, app_wrk->api_client_index,
+			  app_wrk->connects_seg_manager);
+	    else
+	      s = format (s, "%-" SESSION_CLI_ID_LEN "v%-20v", str, app_name);
 
-            vlib_cli_output (vm, "%v", s);
-            vec_reset_length (s);
-            vec_free (str);
+	    vlib_cli_output (vm, "%v", s);
+	    vec_reset_length (s);
+	    vec_free (str);
 
-            f = f->next;
-          }
-        vec_free (s);
+	    f = f->next;
+	  }
+	vec_free (s);
       }
   }
   /* *INDENT-ON* */