session: cleanup segment manager and fifo segment

Change-Id: I984f347fb465c0c405cef668d8690457e81788e2
Signed-off-by: Florin Coras <fcoras@cisco.com>

23 files changed, 1001 insertions, 1005 deletions

diff --git a/src/plugins/unittest/svm_fifo_test.c b/src/plugins/unittest/svm_fifo_test.c
index af806e4782f..163a8e42c68 100644
--- a/src/plugins/unittest/svm_fifo_test.c
+++ b/src/plugins/unittest/svm_fifo_test.c
@@ -13,8 +13,8 @@
  * limitations under the License.
  */
 #include <svm/svm_fifo.h>
-#include <svm/svm_fifo_segment.h>
 #include <vlib/vlib.h>
+#include <svm/fifo_segment.h>
 
 #define SFIFO_TEST_I(_cond, _comment, _args...)			\
 ({								\
@@ -186,7 +186,7 @@ compare_data (u8 * data1, u8 * data2, u32 start, u32 len, u32 * index)
 }
 
 int
-tcp_test_fifo1 (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo1 (vlib_main_t * vm, unformat_input_t * input)
 {
   svm_fifo_t *f;
   u32 fifo_size = 1 << 20;
@@ -423,7 +423,7 @@ err:
 }
 
 static int
-tcp_test_fifo2 (vlib_main_t * vm)
+sfifo_test_fifo2 (vlib_main_t * vm)
 {
   svm_fifo_t *f;
   u32 fifo_size = 1 << 20;
@@ -505,7 +505,7 @@ tcp_test_fifo2 (vlib_main_t * vm)
 }
 
 static int
-tcp_test_fifo3 (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo3 (vlib_main_t * vm, unformat_input_t * input)
 {
   svm_fifo_t *f;
   u32 fifo_size = 4 << 10;
@@ -730,7 +730,7 @@ tcp_test_fifo3 (vlib_main_t * vm, unformat_input_t * input)
 }
 
 static int
-tcp_test_fifo4 (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo4 (vlib_main_t * vm, unformat_input_t * input)
 {
   svm_fifo_t *f;
   u32 fifo_size = 6 << 10;
@@ -803,7 +803,7 @@ fifo_pos (svm_fifo_t * f, u32 pos)
 }
 
 static int
-tcp_test_fifo5 (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo5 (vlib_main_t * vm, unformat_input_t * input)
 {
   svm_fifo_t *f;
   u32 fifo_size = 401, j = 0, offset = 200;
@@ -932,7 +932,7 @@ tcp_test_fifo5 (vlib_main_t * vm, unformat_input_t * input)
 }
 
 static int
-tcp_test_fifo_grow (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo_grow (vlib_main_t * vm, unformat_input_t * input)
 {
   int verbose = 0, fifo_size = 201, start_offset = 100, i, j, rv;
   int test_n_bytes, deq_bytes, enq_bytes, n_deqs, n_enqs;
@@ -1206,7 +1206,7 @@ svm_fifo_trace_elem_t fifo_trace[] = {};
 /* *INDENT-ON* */
 
 static int
-tcp_test_fifo_replay (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo_replay (vlib_main_t * vm, unformat_input_t * input)
 {
   svm_fifo_t f;
   int verbose = 0;
@@ -1236,15 +1236,15 @@ tcp_test_fifo_replay (vlib_main_t * vm, unformat_input_t * input)
   return 0;
 }
 
-static svm_fifo_segment_main_t segment_main;
+static fifo_segment_main_t segment_main;
 
 static int
-tcp_test_fifo_segment_hello_world (int verbose)
+sfifo_test_fifo_segment_hello_world (int verbose)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  svm_fifo_segment_main_t *sm = &segment_main;
+  fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &segment_main;
   u8 *test_data, *retrieved_data = 0;
-  svm_fifo_segment_private_t *sp;
+  fifo_segment_t *sp;
   svm_fifo_t *f;
   int rv;
 
@@ -1252,12 +1252,12 @@ tcp_test_fifo_segment_hello_world (int verbose)
   a->segment_name = "fifo-test1";
   a->segment_size = 256 << 10;
 
-  rv = svm_fifo_segment_create (sm, a);
+  rv = fifo_segment_create (sm, a);
 
   SFIFO_TEST (!rv, "svm_fifo_segment_create returned %d", rv);
 
-  sp = svm_fifo_segment_get_segment (sm, a->new_segment_indices[0]);
-  f = svm_fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FREELIST);
+  sp = fifo_segment_get_segment (sm, a->new_segment_indices[0]);
+  f = fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FIFO);
 
   SFIFO_TEST (f != 0, "svm_fifo_segment_alloc_fifo");
 
@@ -1281,19 +1281,19 @@ tcp_test_fifo_segment_hello_world (int verbose)
 
   vec_free (test_data);
   vec_free (retrieved_data);
-  svm_fifo_segment_free_fifo (sp, f, FIFO_SEGMENT_RX_FREELIST);
-  svm_fifo_segment_delete (sm, sp);
+  fifo_segment_free_fifo (sp, f);
+  fifo_segment_delete (sm, sp);
   return 0;
 }
 
 static int
-tcp_test_fifo_segment_slave (int verbose)
+sfifo_test_fifo_segment_slave (int verbose)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  svm_fifo_segment_main_t *sm = &segment_main;
+  fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &segment_main;
   u8 *test_data, *retrieved_data = 0;
-  svm_fifo_segment_private_t *sp;
-  svm_fifo_segment_header_t *fsh;
+  fifo_segment_t *sp;
+  fifo_segment_header_t *fsh;
   ssvm_shared_header_t *sh;
   svm_fifo_t *f;
   u32 *result;
@@ -1305,13 +1305,13 @@ tcp_test_fifo_segment_slave (int verbose)
   clib_memset (a, 0, sizeof (*a));
   a->segment_name = "fifo-test1";
 
-  rv = svm_fifo_segment_attach (sm, a);
+  rv = fifo_segment_attach (sm, a);
 
   SFIFO_TEST (!rv, "svm_fifo_segment_attach returned %d", rv);
 
-  sp = svm_fifo_segment_get_segment (sm, a->new_segment_indices[0]);
+  sp = fifo_segment_get_segment (sm, a->new_segment_indices[0]);
   sh = sp->ssvm.sh;
-  fsh = (svm_fifo_segment_header_t *) sh->opaque[0];
+  fsh = (fifo_segment_header_t *) sh->opaque[0];
 
   /* might wanna wait.. */
   f = fsh->fifos;
@@ -1340,11 +1340,11 @@ tcp_test_fifo_segment_slave (int verbose)
 }
 
 static int
-tcp_test_fifo_segment_master_slave (int verbose)
+sfifo_test_fifo_segment_master_slave (int verbose)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  svm_fifo_segment_main_t *sm = &segment_main;
-  svm_fifo_segment_private_t *sp;
+  fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &segment_main;
+  fifo_segment_t *sp;
   svm_fifo_t *f;
   u8 *test_data;
   u32 *result;
@@ -1356,18 +1356,18 @@ tcp_test_fifo_segment_master_slave (int verbose)
     SFIFO_TEST (0, "fork failed");
 
   if (!pid)
-    tcp_test_fifo_segment_slave (verbose);
+    sfifo_test_fifo_segment_slave (verbose);
 
   clib_memset (a, 0, sizeof (*a));
   a->segment_name = "fifo-test1";
   a->segment_size = 256 << 10;
 
-  rv = svm_fifo_segment_create (sm, a);
+  rv = fifo_segment_create (sm, a);
 
   SFIFO_TEST (!rv, "svm_fifo_segment_create returned %d", rv);
 
-  sp = svm_fifo_segment_get_segment (sm, a->new_segment_indices[0]);
-  f = svm_fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FREELIST);
+  sp = fifo_segment_get_segment (sm, a->new_segment_indices[0]);
+  f = fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FIFO);
 
   SFIFO_TEST (f != 0, "svm_fifo_segment_alloc_fifo alloc");
 
@@ -1389,17 +1389,17 @@ tcp_test_fifo_segment_master_slave (int verbose)
   SFIFO_TEST (*result == 0, "slave reported no error");
 
   vec_free (test_data);
-  svm_fifo_segment_free_fifo (sp, f, FIFO_SEGMENT_RX_FREELIST);
-  svm_fifo_segment_delete (sm, sp);
+  fifo_segment_free_fifo (sp, f);
+  fifo_segment_delete (sm, sp);
   return 0;
 }
 
 static int
-tcp_test_fifo_segment_mempig (int verbose)
+sfifo_test_fifo_segment_mempig (int verbose)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  svm_fifo_segment_main_t *sm = &segment_main;
-  svm_fifo_segment_private_t *sp;
+  fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &segment_main;
+  fifo_segment_t *sp;
   svm_fifo_t *f;
   svm_fifo_t **flist = 0;
   int rv;
@@ -1410,15 +1410,15 @@ tcp_test_fifo_segment_mempig (int verbose)
   a->segment_name = "fifo-test1";
   a->segment_size = 256 << 10;
 
-  rv = svm_fifo_segment_create (sm, a);
+  rv = fifo_segment_create (sm, a);
 
   SFIFO_TEST (!rv, "svm_fifo_segment_create returned %d", rv);
 
-  sp = svm_fifo_segment_get_segment (sm, a->new_segment_indices[0]);
+  sp = fifo_segment_get_segment (sm, a->new_segment_indices[0]);
 
   for (i = 0; i < 1000; i++)
     {
-      f = svm_fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FREELIST);
+      f = fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FIFO);
       if (f == 0)
 	break;
       vec_add1 (flist, f);
@@ -1429,14 +1429,14 @@ tcp_test_fifo_segment_mempig (int verbose)
   for (i = 0; i < vec_len (flist); i++)
     {
       f = flist[i];
-      svm_fifo_segment_free_fifo (sp, f, FIFO_SEGMENT_RX_FREELIST);
+      fifo_segment_free_fifo (sp, f);
     }
 
   _vec_len (flist) = 0;
 
   for (i = 0; i < 1000; i++)
     {
-      f = svm_fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FREELIST);
+      f = fifo_segment_alloc_fifo (sp, 4096, FIFO_SEGMENT_RX_FIFO);
       if (f == 0)
 	break;
       vec_add1 (flist, f);
@@ -1447,15 +1447,15 @@ tcp_test_fifo_segment_mempig (int verbose)
   for (i = 0; i < vec_len (flist); i++)
     {
       f = flist[i];
-      svm_fifo_segment_free_fifo (sp, f, FIFO_SEGMENT_RX_FREELIST);
+      fifo_segment_free_fifo (sp, f);
     }
 
-  svm_fifo_segment_delete (sm, sp);
+  fifo_segment_delete (sm, sp);
   return 0;
 }
 
 static int
-tcp_test_fifo_segment (vlib_main_t * vm, unformat_input_t * input)
+sfifo_test_fifo_segment (vlib_main_t * vm, unformat_input_t * input)
 {
   int rv, verbose = 0;
 
@@ -1465,27 +1465,27 @@ tcp_test_fifo_segment (vlib_main_t * vm, unformat_input_t * input)
 	verbose = 1;
       else if (unformat (input, "masterslave"))
 	{
-	  if ((rv = tcp_test_fifo_segment_master_slave (verbose)))
+	  if ((rv = sfifo_test_fifo_segment_master_slave (verbose)))
 	    return -1;
 	}
       else if (unformat (input, "basic"))
 	{
-	  if ((rv = tcp_test_fifo_segment_hello_world (verbose)))
+	  if ((rv = sfifo_test_fifo_segment_hello_world (verbose)))
 	    return -1;
 	}
       else if (unformat (input, "mempig"))
 	{
-	  if ((rv = tcp_test_fifo_segment_mempig (verbose)))
+	  if ((rv = sfifo_test_fifo_segment_mempig (verbose)))
 	    return -1;
 	}
       else if (unformat (input, "all"))
 	{
-	  if ((rv = tcp_test_fifo_segment_hello_world (verbose)))
+	  if ((rv = sfifo_test_fifo_segment_hello_world (verbose)))
 	    return -1;
-	  if ((rv = tcp_test_fifo_segment_mempig (verbose)))
+	  if ((rv = sfifo_test_fifo_segment_mempig (verbose)))
 	    return -1;
 	  /* Pretty slow so avoid running it always
-	     if ((rv = tcp_test_fifo_segment_master_slave (verbose)))
+	     if ((rv = sfifo_test_fifo_segment_master_slave (verbose)))
 	     return -1;
 	   */
 	}
@@ -1509,27 +1509,27 @@ svm_fifo_test (vlib_main_t * vm, unformat_input_t * input,
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (input, "fifo1"))
-	res = tcp_test_fifo1 (vm, input);
+	res = sfifo_test_fifo1 (vm, input);
       else if (unformat (input, "fifo2"))
-	res = tcp_test_fifo2 (vm);
+	res = sfifo_test_fifo2 (vm);
       else if (unformat (input, "fifo3"))
-	res = tcp_test_fifo3 (vm, input);
+	res = sfifo_test_fifo3 (vm, input);
       else if (unformat (input, "fifo4"))
-	res = tcp_test_fifo4 (vm, input);
+	res = sfifo_test_fifo4 (vm, input);
       else if (unformat (input, "fifo5"))
-	res = tcp_test_fifo5 (vm, input);
+	res = sfifo_test_fifo5 (vm, input);
       else if (unformat (input, "replay"))
-	res = tcp_test_fifo_replay (vm, input);
+	res = sfifo_test_fifo_replay (vm, input);
       else if (unformat (input, "grow"))
-	res = tcp_test_fifo_grow (vm, input);
+	res = sfifo_test_fifo_grow (vm, input);
       else if (unformat (input, "segment"))
-	res = tcp_test_fifo_segment (vm, input);
+	res = sfifo_test_fifo_segment (vm, input);
       else if (unformat (input, "all"))
 	{
-	  if ((res = tcp_test_fifo1 (vm, input)))
+	  if ((res = sfifo_test_fifo1 (vm, input)))
 	    goto done;
 
-	  if ((res = tcp_test_fifo2 (vm)))
+	  if ((res = sfifo_test_fifo2 (vm)))
 	    goto done;
 
 	  /*
@@ -1537,46 +1537,46 @@ svm_fifo_test (vlib_main_t * vm, unformat_input_t * input,
 	   */
 	  str = "nsegs 10 overlap seed 123";
 	  unformat_init_cstring (input, str);
-	  if ((res = tcp_test_fifo3 (vm, input)))
+	  if ((res = sfifo_test_fifo3 (vm, input)))
 	    goto done;
 	  unformat_free (input);
 
 	  str = "nsegs 10 overlap seed 123 in-seq-all";
 	  unformat_init_cstring (input, str);
-	  if ((res = tcp_test_fifo3 (vm, input)))
+	  if ((res = sfifo_test_fifo3 (vm, input)))
 	    goto done;
 	  unformat_free (input);
 
 	  str = "nsegs 10 overlap seed 123 initial-offset 3917";
 	  unformat_init_cstring (input, str);
-	  if ((res = tcp_test_fifo3 (vm, input)))
+	  if ((res = sfifo_test_fifo3 (vm, input)))
 	    goto done;
 	  unformat_free (input);
 
 	  str = "nsegs 10 overlap seed 123 initial-offset 3917 drop";
 	  unformat_init_cstring (input, str);
-	  if ((res = tcp_test_fifo3 (vm, input)))
+	  if ((res = sfifo_test_fifo3 (vm, input)))
 	    goto done;
 	  unformat_free (input);
 
 	  str = "nsegs 10 seed 123 initial-offset 3917 drop no-randomize";
 	  unformat_init_cstring (input, str);
-	  if ((res = tcp_test_fifo3 (vm, input)))
+	  if ((res = sfifo_test_fifo3 (vm, input)))
 	    goto done;
 	  unformat_free (input);
 
-	  if ((res = tcp_test_fifo4 (vm, input)))
+	  if ((res = sfifo_test_fifo4 (vm, input)))
 	    goto done;
 
-	  if ((res = tcp_test_fifo5 (vm, input)))
+	  if ((res = sfifo_test_fifo5 (vm, input)))
 	    goto done;
 
-	  if ((res = tcp_test_fifo_grow (vm, input)))
+	  if ((res = sfifo_test_fifo_grow (vm, input)))
 	    goto done;
 
 	  str = "all";
 	  unformat_init_cstring (input, str);
-	  if ((res = tcp_test_fifo_segment (vm, input)))
+	  if ((res = sfifo_test_fifo_segment (vm, input)))
 	    goto done;
 	}
       else
diff --git a/src/svm/CMakeLists.txt b/src/svm/CMakeLists.txt
index ab6f7f71954..7664014153a 100644
--- a/src/svm/CMakeLists.txt
+++ b/src/svm/CMakeLists.txt
@@ -16,23 +16,23 @@
 ##############################################################################
 add_vpp_library(svm
   SOURCES
+  fifo_segment.c
+  message_queue.c
+  queue.c
   svm.c
   ssvm.c
   svm_fifo.c
-  svm_fifo_segment.c
-  queue.c
-  message_queue.c
 
   MULTIARCH_SOURCES
   svm_fifo.c
 
   INSTALL_HEADERS
+  fifo_segment.h
+  message_queue.h
+  queue.h
   ssvm.h
   svm_common.h
   svm_fifo.h
-  svm_fifo_segment.h
-  queue.h
-  message_queue.h
   svm.h
   svmdb.h
 
diff --git a/src/svm/svm_fifo_segment.c b/src/svm/fifo_segment.c
index 8a8bd4aa7ff..6bf2634a290 100644
--- a/src/svm/svm_fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -13,190 +13,24 @@
  * limitations under the License.
  */
 
-#include <svm/svm_fifo_segment.h>
-
-static void
-fifo_init_for_segment (svm_fifo_segment_header_t * fsh, u8 * fifo_space,
-		       u32 size, u32 freelist_index)
-{
-  svm_fifo_t *f;
-
-  f = (svm_fifo_t *) fifo_space;
-  f->freelist_index = freelist_index;
-  f->default_chunk.start_byte = 0;
-  f->default_chunk.length = size;
-  f->default_chunk.next = f->start_chunk = f->end_chunk = &f->default_chunk;
-  f->head_chunk = f->tail_chunk = f->ooo_enq = f->ooo_deq = f->start_chunk;
-  f->next = fsh->free_fifos[freelist_index];
-  fsh->free_fifos[freelist_index] = f;
-}
-
-static void
-allocate_new_fifo_chunk (svm_fifo_segment_header_t * fsh,
-			 u32 data_size_in_bytes, int chunk_size)
-{
-  int freelist_index;
-  u32 size;
-  u8 *fifo_space;
-  u32 rounded_data_size;
-  svm_fifo_t *f;
-  int i;
-
-  rounded_data_size = (1 << (max_log2 (data_size_in_bytes)));
-  freelist_index = max_log2 (rounded_data_size)
-    - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
-
-  /* Calculate space requirement $$$ round-up data_size_in_bytes */
-  size = (sizeof (*f) + rounded_data_size) * chunk_size;
-
-  /* Allocate fifo space. May fail. */
-  fifo_space = clib_mem_alloc_aligned_at_offset
-    (size, CLIB_CACHE_LINE_BYTES, 0 /* align_offset */ ,
-     0 /* os_out_of_memory */ );
-
-  /* Out of space.. */
-  if (fifo_space == 0)
-    return;
-
-  /* Carve fifo space */
-  for (i = 0; i < chunk_size; i++)
-    {
-      fifo_init_for_segment (fsh, fifo_space, rounded_data_size,
-			     freelist_index);
-      fifo_space += sizeof (*f) + rounded_data_size;
-    }
-}
-
-/**
- * Pre-allocates fifo pairs in fifo segment
- *
- * The number of fifos pre-allocated is the minimum of the requested number
- * of pairs and the maximum number that fit within the segment. If the maximum
- * is hit, the number of fifo pairs requested is updated by subtracting the
- * number of fifos that have been successfully allocated.
- */
-void
-svm_fifo_segment_preallocate_fifo_pairs (svm_fifo_segment_private_t * s,
-					 u32 rx_fifo_size, u32 tx_fifo_size,
-					 u32 * n_fifo_pairs)
-{
-  u32 rx_rounded_data_size, tx_rounded_data_size, pair_size;
-  u32 rx_fifos_size, tx_fifos_size, pairs_to_allocate;
-  int rx_freelist_index, tx_freelist_index;
-  ssvm_shared_header_t *sh = s->ssvm.sh;
-  svm_fifo_segment_header_t *fsh = s->h;
-  u8 *rx_fifo_space, *tx_fifo_space;
-  uword space_available;
-  void *oldheap;
-  svm_fifo_t *f;
-  int i;
-
-  /* Parameter check */
-  if (rx_fifo_size == 0 || tx_fifo_size == 0 || *n_fifo_pairs == 0)
-    return;
-
-  if (rx_fifo_size < FIFO_SEGMENT_MIN_FIFO_SIZE ||
-      rx_fifo_size > FIFO_SEGMENT_MAX_FIFO_SIZE)
-    {
-      clib_warning ("rx fifo_size out of range %d", rx_fifo_size);
-      return;
-    }
-
-  if (tx_fifo_size < FIFO_SEGMENT_MIN_FIFO_SIZE ||
-      tx_fifo_size > FIFO_SEGMENT_MAX_FIFO_SIZE)
-    {
-      clib_warning ("tx fifo_size out of range %d", rx_fifo_size);
-      return;
-    }
-
-  rx_rounded_data_size = (1 << (max_log2 (rx_fifo_size)));
-  rx_freelist_index = max_log2 (rx_fifo_size)
-    - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
-  tx_rounded_data_size = (1 << (max_log2 (tx_fifo_size)));
-  tx_freelist_index = max_log2 (tx_fifo_size)
-    - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
-
-  /* Calculate space requirements */
-  pair_size = 2 * sizeof (*f) + rx_rounded_data_size + tx_rounded_data_size;
-#if USE_DLMALLOC == 0
-  space_available = s->ssvm.ssvm_size - mheap_bytes (sh->heap);
-#else
-  space_available = s->ssvm.ssvm_size - mspace_usable_size (sh->heap);
-#endif
-
-  pairs_to_allocate = clib_min (space_available / pair_size, *n_fifo_pairs);
-  rx_fifos_size = (sizeof (*f) + rx_rounded_data_size) * pairs_to_allocate;
-  tx_fifos_size = (sizeof (*f) + tx_rounded_data_size) * pairs_to_allocate;
-
-  vec_validate_init_empty (fsh->free_fifos,
-			   clib_max (rx_freelist_index, tx_freelist_index),
-			   0);
-
-  oldheap = ssvm_push_heap (sh);
-  /* Allocate rx fifo space. May fail. */
-  rx_fifo_space = clib_mem_alloc_aligned_at_offset
-    (rx_fifos_size, CLIB_CACHE_LINE_BYTES, 0 /* align_offset */ ,
-     0 /* os_out_of_memory */ );
-
-  /* Same for TX */
-  tx_fifo_space = clib_mem_alloc_aligned_at_offset
-    (tx_fifos_size, CLIB_CACHE_LINE_BYTES, 0 /* align_offset */ ,
-     0 /* os_out_of_memory */ );
-
-  /* Make sure it worked. Clean up if it didn't... */
-  if (rx_fifo_space == 0 || tx_fifo_space == 0)
-    {
-      if (rx_fifo_space)
-	clib_mem_free (rx_fifo_space);
-      else
-	clib_warning ("rx fifo preallocation failure: size %d npairs %d",
-		      rx_fifo_size, *n_fifo_pairs);
-
-      if (tx_fifo_space)
-	clib_mem_free (tx_fifo_space);
-      else
-	clib_warning ("tx fifo preallocation failure: size %d nfifos %d",
-		      tx_fifo_size, *n_fifo_pairs);
-      ssvm_pop_heap (oldheap);
-      return;
-    }
-
-  /* Carve rx fifo space */
-  for (i = 0; i < pairs_to_allocate; i++)
-    {
-      fifo_init_for_segment (fsh, rx_fifo_space, rx_rounded_data_size,
-			     rx_freelist_index);
-      rx_fifo_space += sizeof (*f) + rx_rounded_data_size;
-    }
-  /* Carve tx fifo space */
-  for (i = 0; i < pairs_to_allocate; i++)
-    {
-      fifo_init_for_segment (fsh, tx_fifo_space, tx_rounded_data_size,
-			     tx_freelist_index);
-      tx_fifo_space += sizeof (*f) + tx_rounded_data_size;
-    }
-
-  /* Account for the pairs allocated */
-  *n_fifo_pairs -= pairs_to_allocate;
-  ssvm_pop_heap (oldheap);
-}
+#include <svm/fifo_segment.h>
 
 /**
- * Initialize svm fifo segment shared header
+ * Initialize fifo segment shared header
  */
 int
-svm_fifo_segment_init (svm_fifo_segment_private_t * s)
+fifo_segment_init (fifo_segment_t * fs)
 {
-  svm_fifo_segment_header_t *fsh;
+  fifo_segment_header_t *fsh;
   ssvm_shared_header_t *sh;
   void *oldheap;
 
-  sh = s->ssvm.sh;
+  sh = fs->ssvm.sh;
   oldheap = ssvm_push_heap (sh);
 
   fsh = clib_mem_alloc (sizeof (*fsh));
   clib_memset (fsh, 0, sizeof (*fsh));
-  s->h = sh->opaque[0] = fsh;
+  fs->h = sh->opaque[0] = fsh;
 
   ssvm_pop_heap (oldheap);
 
@@ -205,51 +39,17 @@ svm_fifo_segment_init (svm_fifo_segment_private_t * s)
 }
 
 /**
- * Create an svm fifo segment and initialize as master
+ * Create a fifo segment in process-private memory
  */
-int
-svm_fifo_segment_create (svm_fifo_segment_main_t * sm,
-			 svm_fifo_segment_create_args_t * a)
+static int
+fifo_segment_create_process_private (fifo_segment_main_t * sm,
+				     fifo_segment_create_args_t * a)
 {
-  svm_fifo_segment_private_t *s;
-  int rv;
-
-  /* Allocate a fresh segment */
-  pool_get (sm->segments, s);
-  clib_memset (s, 0, sizeof (*s));
-
-  s->ssvm.ssvm_size = a->segment_size;
-  s->ssvm.i_am_master = 1;
-  s->ssvm.my_pid = getpid ();
-  s->ssvm.name = format (0, "%s%c", a->segment_name, 0);
-  s->ssvm.requested_va = sm->next_baseva;
-
-  if ((rv = ssvm_master_init (&s->ssvm, a->segment_type)))
-    {
-      pool_put (sm->segments, s);
-      return (rv);
-    }
-
-  /* Note: requested_va updated due to seg base addr randomization */
-  sm->next_baseva = s->ssvm.sh->ssvm_va + a->segment_size;
-
-  svm_fifo_segment_init (s);
-  vec_add1 (a->new_segment_indices, s - sm->segments);
-  return (0);
-}
-
-/**
- * Create an svm fifo segment in process-private memory
- */
-int
-svm_fifo_segment_create_process_private (svm_fifo_segment_main_t * sm,
-					 svm_fifo_segment_create_args_t * a)
-{
-  svm_fifo_segment_private_t *s;
+  u32 pagesize = clib_mem_get_page_size ();
   ssvm_shared_header_t *sh;
+  fifo_segment_t *s;
   u32 rnd_size = 0;
   u8 *heap;
-  u32 pagesize = clib_mem_get_page_size ();
 
   pool_get (sm->segments, s);
   clib_memset (s, 0, sizeof (*s));
@@ -286,27 +86,60 @@ svm_fifo_segment_create_process_private (svm_fifo_segment_main_t * sm,
   clib_memset (sh, 0, sizeof (*sh));
   sh->heap = heap;
 
-  svm_fifo_segment_init (s);
+  fifo_segment_init (s);
   vec_add1 (a->new_segment_indices, s - sm->segments);
 
   return (0);
 }
 
 /**
- * Attach as slave to an svm fifo segment
+ * Create a fifo segment and initialize as master
  */
 int
-svm_fifo_segment_attach (svm_fifo_segment_main_t * sm,
-			 svm_fifo_segment_create_args_t * a)
+fifo_segment_create (fifo_segment_main_t * sm, fifo_segment_create_args_t * a)
 {
-  svm_fifo_segment_private_t *s;
+  fifo_segment_t *s;
   int rv;
 
+  if (a->segment_type == SSVM_SEGMENT_PRIVATE)
+    return fifo_segment_create_process_private (sm, a);
+
   /* Allocate a fresh segment */
   pool_get (sm->segments, s);
   clib_memset (s, 0, sizeof (*s));
 
   s->ssvm.ssvm_size = a->segment_size;
+  s->ssvm.i_am_master = 1;
+  s->ssvm.my_pid = getpid ();
+  s->ssvm.name = format (0, "%s%c", a->segment_name, 0);
+  s->ssvm.requested_va = sm->next_baseva;
+
+  if ((rv = ssvm_master_init (&s->ssvm, a->segment_type)))
+    {
+      pool_put (sm->segments, s);
+      return (rv);
+    }
+
+  /* Note: requested_va updated due to seg base addr randomization */
+  sm->next_baseva = s->ssvm.sh->ssvm_va + a->segment_size;
+
+  fifo_segment_init (s);
+  vec_add1 (a->new_segment_indices, s - sm->segments);
+  return (0);
+}
+
+/**
+ * Attach as slave to a fifo segment
+ */
+int
+fifo_segment_attach (fifo_segment_main_t * sm, fifo_segment_create_args_t * a)
+{
+  fifo_segment_t *s;
+  int rv;
+
+  pool_get_zero (sm->segments, s);
+
+  s->ssvm.ssvm_size = a->segment_size;
   s->ssvm.my_pid = getpid ();
   s->ssvm.name = format (0, "%s%c", a->segment_name, 0);
   s->ssvm.requested_va = sm->next_baseva;
@@ -329,92 +162,187 @@ svm_fifo_segment_attach (svm_fifo_segment_main_t * sm,
 }
 
 void
-svm_fifo_segment_delete (svm_fifo_segment_main_t * sm,
-			 svm_fifo_segment_private_t * s)
+fifo_segment_delete (fifo_segment_main_t * sm, fifo_segment_t * s)
 {
   ssvm_delete (&s->ssvm);
   clib_memset (s, 0xfe, sizeof (*s));
   pool_put (sm->segments, s);
 }
 
+u32
+fifo_segment_index (fifo_segment_main_t * sm, fifo_segment_t * s)
+{
+  return s - sm->segments;
+}
+
+void *
+svm_fifo_segment_heap (fifo_segment_t * seg)
+{
+  return seg->ssvm.sh->heap;
+}
+
+fifo_segment_t *
+fifo_segment_get_segment (fifo_segment_main_t * sm, u32 segment_index)
+{
+  return pool_elt_at_index (sm->segments, segment_index);
+}
+
+void
+fifo_segment_info (fifo_segment_t * seg, char **address, size_t * size)
+{
+  if (ssvm_type (&seg->ssvm) == SSVM_SEGMENT_PRIVATE)
+    {
+#if USE_DLMALLOC == 0
+      mheap_t *heap_header;
+
+      *address = pointer_to_uword (seg->ssvm.sh->heap);
+      heap_header = mheap_header (seg->ssvm.sh->heap);
+      *size = heap_header->max_size;
+#else
+      mspace_get_address_and_size (seg->ssvm.sh->heap, address, size);
+#endif
+    }
+  else
+    {
+      *address = (char *) seg->ssvm.sh->ssvm_va;
+      *size = seg->ssvm.ssvm_size;
+    }
+}
+
+void
+fifo_segment_main_init (fifo_segment_main_t * sm, u64 baseva,
+			u32 timeout_in_seconds)
+{
+  sm->next_baseva = baseva;
+  sm->timeout_in_seconds = timeout_in_seconds;
+}
+
+static void
+fifo_init_for_segment (fifo_segment_header_t * fsh, svm_fifo_t * f,
+		       u32 size, u32 fl_index)
+{
+  f->freelist_index = fl_index;
+  f->default_chunk.start_byte = 0;
+  f->default_chunk.length = size;
+  f->default_chunk.next = f->start_chunk = f->end_chunk = &f->default_chunk;
+  f->head_chunk = f->tail_chunk = f->ooo_enq = f->ooo_deq = f->start_chunk;
+  f->next = fsh->free_fifos[fl_index];
+  fsh->free_fifos[fl_index] = f;
+}
+
+static inline int
+fs_free_list_for_size (u32 size)
+{
+  return max_log2 (size) - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
+}
+
+static inline int
+fs_fifo_size_is_valid (u32 size)
+{
+  /*
+   * 4K minimum. It's not likely that anything good will happen
+   * with a smaller FIFO.
+   */
+  return size >= FIFO_SEGMENT_MIN_FIFO_SIZE
+    && size <= FIFO_SEGMENT_MAX_FIFO_SIZE;
+}
+
+static void
+allocate_new_fifo_batch (fifo_segment_header_t * fsh,
+			 u32 data_size_in_bytes, int chunk_size)
+{
+  u32 size, rounded_data_size;
+  int i, fl_index;
+  u8 *fifos_mem;
+  svm_fifo_t *f;
+
+  rounded_data_size = (1 << (max_log2 (data_size_in_bytes)));
+  fl_index = fs_free_list_for_size (data_size_in_bytes);
+
+  /* Calculate space requirement $$$ round-up data_size_in_bytes */
+  size = (sizeof (*f) + rounded_data_size) * chunk_size;
+
+  /* Allocate fifo space. May fail. */
+  fifos_mem = clib_mem_alloc_aligned_at_offset (size, CLIB_CACHE_LINE_BYTES,
+						0 /* align_offset */ ,
+						0 /* os_out_of_memory */ );
+
+  /* Out of space.. */
+  if (fifos_mem == 0)
+    return;
+
+  /* Carve fifo space */
+  for (i = 0; i < chunk_size; i++)
+    {
+      f = (svm_fifo_t *) fifos_mem;
+      fifo_init_for_segment (fsh, f, rounded_data_size, fl_index);
+      fifos_mem += sizeof (*f) + rounded_data_size;
+    }
+}
+
 /**
- * Allocate fifo in svm segment
+ * Allocate fifo in fifo segment
  */
 svm_fifo_t *
-svm_fifo_segment_alloc_fifo (svm_fifo_segment_private_t * fs,
-			     u32 data_size_in_bytes,
-			     svm_fifo_segment_freelist_t list_index)
+fifo_segment_alloc_fifo (fifo_segment_t * fs, u32 data_bytes,
+			 fifo_segment_ftype_t ftype)
 {
+  fifo_segment_header_t *fsh;
   ssvm_shared_header_t *sh;
-  svm_fifo_segment_header_t *fsh;
   svm_fifo_t *f = 0;
   void *oldheap;
-  int freelist_index;
+  int fl_index;
 
-  /*
-   * 4K minimum. It's not likely that anything good will happen
-   * with a smaller FIFO.
-   */
-  if (data_size_in_bytes < FIFO_SEGMENT_MIN_FIFO_SIZE ||
-      data_size_in_bytes > FIFO_SEGMENT_MAX_FIFO_SIZE)
+  if (!fs_fifo_size_is_valid (data_bytes))
     {
-      clib_warning ("fifo size out of range %d", data_size_in_bytes);
+      clib_warning ("fifo size out of range %d", data_bytes);
       return 0;
     }
 
-  freelist_index = max_log2 (data_size_in_bytes)
-    - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
+  fl_index = fs_free_list_for_size (data_bytes);
 
   sh = fs->ssvm.sh;
   ssvm_lock_non_recursive (sh, 1);
-  fsh = (svm_fifo_segment_header_t *) sh->opaque[0];
 
-  switch (list_index)
-    {
-    case FIFO_SEGMENT_RX_FREELIST:
-    case FIFO_SEGMENT_TX_FREELIST:
-      vec_validate_init_empty (fsh->free_fifos, freelist_index, 0);
-      f = fsh->free_fifos[freelist_index];
-      if (PREDICT_FALSE (!f))
-	{
-	  oldheap = ssvm_push_heap (sh);
-	  allocate_new_fifo_chunk (fsh, data_size_in_bytes,
-				   FIFO_SEGMENT_ALLOC_CHUNK_SIZE);
-	  ssvm_pop_heap (oldheap);
-	  f = fsh->free_fifos[freelist_index];
-	}
-      if (PREDICT_TRUE (f != 0))
-	{
-	  fsh->free_fifos[freelist_index] = f->next;
-	  /* (re)initialize the fifo, as in svm_fifo_create */
-	  clib_memset (f, 0, sizeof (*f));
-	  svm_fifo_init (f, data_size_in_bytes);
-	  goto found;
-	}
-      break;
-    case FIFO_SEGMENT_FREELIST_NONE:
-      break;
+  fsh = (fifo_segment_header_t *) sh->opaque[0];
+  vec_validate_init_empty (fsh->free_fifos, fl_index, 0);
+  f = fsh->free_fifos[fl_index];
 
-    default:
-      clib_warning ("ignore bogus freelist %d", list_index);
-      break;
+  /* Try to allocate batch of fifos */
+  if (PREDICT_FALSE (!f))
+    {
+      oldheap = ssvm_push_heap (sh);
+      allocate_new_fifo_batch (fsh, data_bytes,
+			       FIFO_SEGMENT_ALLOC_BATCH_SIZE);
+      ssvm_pop_heap (oldheap);
+      f = fsh->free_fifos[fl_index];
+    }
+  if (PREDICT_TRUE (f != 0))
+    {
+      fsh->free_fifos[fl_index] = f->next;
+      /* (re)initialize the fifo, as in svm_fifo_create */
+      memset (f, 0, sizeof (*f));
+      svm_fifo_init (f, data_bytes);
+      goto found;
     }
 
-  /* Catch all that allocates just one fifo. Note: this can fail,
-   * in which case: create another segment */
+  /* Failed to allocate batch, try just one fifo. This can also fail,
+   * in which case, create another segment */
   oldheap = ssvm_push_heap (sh);
-  f = svm_fifo_create (data_size_in_bytes);
+  f = svm_fifo_create (data_bytes);
   ssvm_pop_heap (oldheap);
+
   if (PREDICT_FALSE (f == 0))
     goto done;
-  f->freelist_index = freelist_index;
+
+  f->freelist_index = fl_index;
 
 found:
-  /* If rx_freelist add to active fifos list. When cleaning up segment,
+  /* If rx fifo type add to active fifos list. When cleaning up segment,
    * we need a list of active sessions that should be disconnected. Since
    * both rx and tx fifos keep pointers to the session, it's enough to track
    * only one. */
-  if (list_index == FIFO_SEGMENT_RX_FREELIST)
+  if (ftype == FIFO_SEGMENT_RX_FIFO)
     {
       if (fsh->fifos)
 	{
@@ -422,6 +350,7 @@ found:
 	  f->next = fsh->fifos;
 	}
       fsh->fifos = f;
+      f->flags |= SVM_FIFO_F_LL_TRACKED;
     }
   fsh->n_active_fifos++;
 
@@ -430,13 +359,15 @@ done:
   return (f);
 }
 
+/**
+ * Free fifo allocated in fifo segment
+ */
 void
-svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s, svm_fifo_t * f,
-			    svm_fifo_segment_freelist_t list_index)
+fifo_segment_free_fifo (fifo_segment_t * s, svm_fifo_t * f)
 {
+  fifo_segment_header_t *fsh;
   ssvm_shared_header_t *sh;
-  svm_fifo_segment_header_t *fsh;
-  int freelist_index;
+  int fl_index;
 
   ASSERT (f->refcnt > 0);
 
@@ -444,39 +375,30 @@ svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s, svm_fifo_t * f,
     return;
 
   sh = s->ssvm.sh;
-  fsh = (svm_fifo_segment_header_t *) sh->opaque[0];
-
-  freelist_index = f->freelist_index;
+  fsh = (fifo_segment_header_t *) sh->opaque[0];
+  fl_index = f->freelist_index;
 
-  ASSERT (freelist_index < vec_len (fsh->free_fifos));
+  ASSERT (fl_index < vec_len (fsh->free_fifos));
 
   ssvm_lock_non_recursive (sh, 2);
 
-  switch (list_index)
+  /* Remove from active list. Only rx fifos are tracked */
+  if (f->flags & SVM_FIFO_F_LL_TRACKED)
     {
-    case FIFO_SEGMENT_RX_FREELIST:
-      /* Remove from active list */
       if (f->prev)
 	f->prev->next = f->next;
       else
 	fsh->fifos = f->next;
       if (f->next)
 	f->next->prev = f->prev;
-      /* Fall through: we add only rx fifos to active pool */
-    case FIFO_SEGMENT_TX_FREELIST:
-      /* Add to free list */
-      f->next = fsh->free_fifos[freelist_index];
-      f->prev = 0;
-      fsh->free_fifos[freelist_index] = f;
-      break;
-    case FIFO_SEGMENT_FREELIST_NONE:
-      break;
-
-    default:
-      clib_warning ("ignore bogus freelist %d", list_index);
-      break;
+      f->flags &= ~SVM_FIFO_F_LL_TRACKED;
     }
 
+  /* Add to free list */
+  f->next = fsh->free_fifos[fl_index];
+  f->prev = 0;
+  fsh->free_fifos[fl_index] = f;
+
   if (CLIB_DEBUG)
     {
       f->master_session_index = ~0;
@@ -487,51 +409,119 @@ svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s, svm_fifo_t * f,
   ssvm_unlock_non_recursive (sh);
 }
 
+/**
+ * Pre-allocates fifo pairs in fifo segment
+ */
 void
-svm_fifo_segment_main_init (svm_fifo_segment_main_t * sm, u64 baseva,
-			    u32 timeout_in_seconds)
+fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
+				     u32 rx_fifo_size, u32 tx_fifo_size,
+				     u32 * n_fifo_pairs)
 {
-  sm->next_baseva = baseva;
-  sm->timeout_in_seconds = timeout_in_seconds;
-}
+  u32 rx_rounded_data_size, tx_rounded_data_size, pair_size;
+  u32 rx_fifos_size, tx_fifos_size, pairs_to_allocate;
+  ssvm_shared_header_t *sh = fs->ssvm.sh;
+  fifo_segment_header_t *fsh = fs->h;
+  int i, rx_fl_index, tx_fl_index;
+  u8 *rx_fifo_mem, *tx_fifo_mem;
+  uword space_available;
+  void *oldheap;
+  svm_fifo_t *f;
 
-u32
-svm_fifo_segment_index (svm_fifo_segment_main_t * sm,
-			svm_fifo_segment_private_t * s)
-{
-  return s - sm->segments;
-}
+  /* Parameter check */
+  if (rx_fifo_size == 0 || tx_fifo_size == 0 || *n_fifo_pairs == 0)
+    return;
 
-/**
- * Retrieve svm segments pool. Used only for debug purposes.
- */
-svm_fifo_segment_private_t *
-svm_fifo_segment_segments_pool (svm_fifo_segment_main_t * sm)
-{
-  return sm->segments;
+  if (!fs_fifo_size_is_valid (rx_fifo_size))
+    {
+      clib_warning ("rx fifo_size out of range %d", rx_fifo_size);
+      return;
+    }
+
+  if (!fs_fifo_size_is_valid (tx_fifo_size))
+    {
+      clib_warning ("tx fifo_size out of range %d", tx_fifo_size);
+      return;
+    }
+
+  rx_rounded_data_size = (1 << (max_log2 (rx_fifo_size)));
+  rx_fl_index = fs_free_list_for_size (rx_fifo_size);
+  tx_rounded_data_size = (1 << (max_log2 (tx_fifo_size)));
+  tx_fl_index = fs_free_list_for_size (tx_fifo_size);
+
+  /* Calculate space requirements */
+  pair_size = 2 * sizeof (*f) + rx_rounded_data_size + tx_rounded_data_size;
+#if USE_DLMALLOC == 0
+  space_available = fs->ssvm.ssvm_size - mheap_bytes (sh->heap);
+#else
+  space_available = fs->ssvm.ssvm_size - mspace_usable_size (sh->heap);
+#endif
+
+  pairs_to_allocate = clib_min (space_available / pair_size, *n_fifo_pairs);
+  rx_fifos_size = (sizeof (*f) + rx_rounded_data_size) * pairs_to_allocate;
+  tx_fifos_size = (sizeof (*f) + tx_rounded_data_size) * pairs_to_allocate;
+
+  vec_validate_init_empty (fsh->free_fifos,
+			   clib_max (rx_fl_index, tx_fl_index), 0);
+
+  oldheap = ssvm_push_heap (sh);
+
+  /* Allocate rx and tx fifo memory. May fail. */
+  rx_fifo_mem = clib_mem_alloc_aligned_at_offset (rx_fifos_size,
+						  CLIB_CACHE_LINE_BYTES,
+						  0 /* align_offset */ ,
+						  0 /* os_out_of_memory */ );
+  tx_fifo_mem = clib_mem_alloc_aligned_at_offset (tx_fifos_size,
+						  CLIB_CACHE_LINE_BYTES,
+						  0 /* align_offset */ ,
+						  0 /* os_out_of_memory */ );
+
+  /* Make sure it worked. Clean up if it didn't... */
+  if (rx_fifo_mem == 0 || tx_fifo_mem == 0)
+    {
+      rx_fifo_mem ? clib_mem_free (rx_fifo_mem) : clib_mem_free (tx_fifo_mem);
+      clib_warning ("fifo preallocation failure: rx size %d tx size %u "
+		    "npairs %d", rx_fifo_size, tx_fifo_size, *n_fifo_pairs);
+      ssvm_pop_heap (oldheap);
+      return;
+    }
+
+  /* Carve rx and tx fifo memory */
+  for (i = 0; i < pairs_to_allocate; i++)
+    {
+      f = (svm_fifo_t *) rx_fifo_mem;
+      fifo_init_for_segment (fsh, f, rx_rounded_data_size, rx_fl_index);
+      rx_fifo_mem += sizeof (*f) + rx_rounded_data_size;
+
+      f = (svm_fifo_t *) tx_fifo_mem;
+      fifo_init_for_segment (fsh, f, tx_rounded_data_size, tx_fl_index);
+      tx_fifo_mem += sizeof (*f) + tx_rounded_data_size;
+    }
+
+  /* Account for the pairs allocated */
+  *n_fifo_pairs -= pairs_to_allocate;
+  ssvm_pop_heap (oldheap);
 }
 
 /**
  * Get number of active fifos
  */
 u32
-svm_fifo_segment_num_fifos (svm_fifo_segment_private_t * fifo_segment)
+fifo_segment_num_fifos (fifo_segment_t * fs)
 {
-  return fifo_segment->h->n_active_fifos;
+  return fs->h->n_active_fifos;
 }
 
 u32
-svm_fifo_segment_num_free_fifos (svm_fifo_segment_private_t * fifo_segment,
-				 u32 fifo_size_in_bytes)
+fifo_segment_num_free_fifos (fifo_segment_t * fs, u32 fifo_size_in_bytes)
 {
+  u32 count = 0, rounded_data_size, fl_index;
+  fifo_segment_header_t *fsh;
   ssvm_shared_header_t *sh;
-  svm_fifo_segment_header_t *fsh;
   svm_fifo_t *f;
   int i;
-  u32 count = 0, rounded_data_size, freelist_index;
 
-  sh = fifo_segment->ssvm.sh;
-  fsh = (svm_fifo_segment_header_t *) sh->opaque[0];
+  sh = fs->ssvm.sh;
+  fsh = (fifo_segment_header_t *) sh->opaque[0];
 
   /* Count all free fifos? */
   if (fifo_size_in_bytes == ~0)
@@ -552,13 +542,12 @@ svm_fifo_segment_num_free_fifos (svm_fifo_segment_private_t * fifo_segment,
     }
 
   rounded_data_size = (1 << (max_log2 (fifo_size_in_bytes)));
-  freelist_index = max_log2 (rounded_data_size)
-    - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
+  fl_index = fs_free_list_for_size (rounded_data_size);
 
-  if (freelist_index >= vec_len (fsh->free_fifos))
+  if (fl_index >= vec_len (fsh->free_fifos))
     return 0;
 
-  f = fsh->free_fifos[freelist_index];
+  f = fsh->free_fifos[fl_index];
   if (f == 0)
     return 0;
 
@@ -570,40 +559,23 @@ svm_fifo_segment_num_free_fifos (svm_fifo_segment_private_t * fifo_segment,
   return count;
 }
 
-void
-svm_fifo_segment_info (svm_fifo_segment_private_t * seg, char **address,
-		       size_t * size)
+u8
+fifo_segment_has_fifos (fifo_segment_t * fs)
 {
-  if (ssvm_type (&seg->ssvm) == SSVM_SEGMENT_PRIVATE)
-    {
-#if USE_DLMALLOC == 0
-      mheap_t *heap_header;
-
-      *address = pointer_to_uword (seg->ssvm.sh->heap);
-      heap_header = mheap_header (seg->ssvm.sh->heap);
-      *size = heap_header->max_size;
-#else
-      mspace_get_address_and_size (seg->ssvm.sh->heap, address, size);
-#endif
-    }
-  else
-    {
-      *address = (char *) seg->ssvm.sh->ssvm_va;
-      *size = seg->ssvm.ssvm_size;
-    }
+  return fs->h->fifos != 0;
 }
 
-void *
-svm_fifo_segment_heap (svm_fifo_segment_private_t * seg)
+svm_fifo_t *
+fifo_segment_get_fifo_list (fifo_segment_t * fs)
 {
-  return seg->ssvm.sh->heap;
+  return fs->h->fifos;
 }
 
 u8 *
-format_svm_fifo_segment_type (u8 * s, va_list * args)
+format_fifo_segment_type (u8 * s, va_list * args)
 {
-  svm_fifo_segment_private_t *sp;
-  sp = va_arg (*args, svm_fifo_segment_private_t *);
+  fifo_segment_t *sp;
+  sp = va_arg (*args, fifo_segment_t *);
   ssvm_segment_type_t st = ssvm_type (&sp->ssvm);
 
   if (st == SSVM_SEGMENT_PRIVATE)
@@ -621,12 +593,11 @@ format_svm_fifo_segment_type (u8 * s, va_list * args)
  * Segment format function
  */
 u8 *
-format_svm_fifo_segment (u8 * s, va_list * args)
+format_fifo_segment (u8 * s, va_list * args)
 {
-  svm_fifo_segment_private_t *sp
-    = va_arg (*args, svm_fifo_segment_private_t *);
+  fifo_segment_t *sp = va_arg (*args, fifo_segment_t *);
   int verbose __attribute__ ((unused)) = va_arg (*args, int);
-  svm_fifo_segment_header_t *fsh = sp->h;
+  fifo_segment_header_t *fsh = sp->h;
   u32 count, indent;
   svm_fifo_t *f;
   int i;
@@ -636,7 +607,7 @@ format_svm_fifo_segment (u8 * s, va_list * args)
   s = format (s, "%U segment heap: %U\n", format_white_space, indent,
 	      format_mheap, svm_fifo_segment_heap (sp), verbose);
   s = format (s, "%U segment has %u active fifos\n",
-	      format_white_space, indent, svm_fifo_segment_num_fifos (sp));
+	      format_white_space, indent, fifo_segment_num_fifos (sp));
 #endif
 
   for (i = 0; i < vec_len (fsh->free_fifos); i++)
diff --git a/src/svm/fifo_segment.h b/src/svm/fifo_segment.h
new file mode 100644
index 00000000000..cc0ff3adf3a
--- /dev/null
+++ b/src/svm/fifo_segment.h
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2016-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef __included_fifo_segment_h__
+#define __included_fifo_segment_h__
+
+#include <svm/ssvm.h>
+#include <svm/svm_fifo.h>
+
+typedef enum
+{
+  FIFO_SEGMENT_FTYPE_NONE = -1,
+  FIFO_SEGMENT_RX_FIFO = 0,
+  FIFO_SEGMENT_TX_FIFO,
+  FIFO_SEGMENT_N_FTYPES
+} fifo_segment_ftype_t;
+
+#define FIFO_SEGMENT_MIN_FIFO_SIZE 4096	/* 4kB min fifo size */
+#define FIFO_SEGMENT_MAX_FIFO_SIZE (2 << 30)	/* 2GB max fifo size */
+#define FIFO_SEGMENT_ALLOC_BATCH_SIZE 32	/* Allocation quantum */
+
+typedef enum fifo_segment_flags_
+{
+  FIFO_SEGMENT_F_IS_PREALLOCATED = 1 << 0,
+  FIFO_SEGMENT_F_WILL_DELETE = 1 << 1,
+} fifo_segment_flags_t;
+
+typedef struct
+{
+  svm_fifo_t *fifos;		/**< Linked list of active RX fifos */
+  svm_fifo_t **free_fifos;	/**< Freelists, by fifo size  */
+  u32 n_active_fifos;		/**< Number of active fifos */
+  u8 flags;			/**< Segment flags */
+} fifo_segment_header_t;
+
+typedef struct
+{
+  ssvm_private_t ssvm;		/**< ssvm segment data */
+  fifo_segment_header_t *h;	/**< fifo segment data */
+} fifo_segment_t;
+
+typedef struct
+{
+  fifo_segment_t *segments;	/**< pool of fifo segments */
+  u64 next_baseva;		/**< Where to put the next one */
+  u32 timeout_in_seconds;	/**< Time to wait during attach */
+} fifo_segment_main_t;
+
+typedef struct
+{
+  ssvm_segment_type_t segment_type;	/**< type of segment requested */
+  u32 segment_size;			/**< size of the segment */
+  int memfd_fd;				/**< fd for memfd segments */
+  char *segment_name;			/**< segment name */
+  u32 *new_segment_indices;		/**< return vec of new seg indices */
+} fifo_segment_create_args_t;
+
+#define fifo_segment_flags(_fs) _fs->h->flags
+
+int fifo_segment_init (fifo_segment_t * fs);
+int fifo_segment_create (fifo_segment_main_t * sm,
+			 fifo_segment_create_args_t * a);
+int fifo_segment_attach (fifo_segment_main_t * sm,
+			 fifo_segment_create_args_t * a);
+void fifo_segment_delete (fifo_segment_main_t * sm, fifo_segment_t * fs);
+fifo_segment_t *fifo_segment_get_segment (fifo_segment_main_t * sm,
+					  u32 fs_index);
+u32 fifo_segment_index (fifo_segment_main_t * sm, fifo_segment_t * fs);
+void fifo_segment_info (fifo_segment_t * seg, char **address, size_t * size);
+
+/**
+ * Allocate fifo in fifo segment
+ *
+ * @param fs		fifo segment
+ * @param data_bytes	size of default fifo chunk in bytes
+ * @param ftype		fifo type @ref fifo_segment_ftype_t
+ * @return		new fifo or 0 if alloc failed
+ */
+svm_fifo_t *fifo_segment_alloc_fifo (fifo_segment_t * fs,
+				     u32 data_bytes,
+				     fifo_segment_ftype_t ftype);
+
+/**
+ * Free fifo allocated in fifo segment
+ *
+ * @param fs		fifo segment
+ * @param f		fifo to be freed
+ */
+void fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f);
+
+/**
+ * Pre-allocates fifo pairs in fifo segment
+ *
+ * The number of fifos pre-allocated is the minimum of the requested number
+ * of pairs and the maximum number that fit within the segment. If the maximum
+ * is hit, the number of fifo pairs requested is updated by subtracting the
+ * number of fifos that have been successfully allocated.
+ *
+ * @param fs		fifo segment
+ * @param rx_fifo_size	data size of rx fifos
+ * @param tx_fifo_size	data size of tx fifos
+ * @param n_fifo_pairs	number of pairs requested. Prior to returning, this
+ * 			is decremented by the the number of pairs allocated.
+ */
+void fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
+					  u32 rx_fifo_size,
+					  u32 tx_fifo_size,
+					  u32 * n_fifo_pairs);
+u8 fifo_segment_has_fifos (fifo_segment_t * fs);
+svm_fifo_t *fifo_segment_get_fifo_list (fifo_segment_t * fs);
+u32 fifo_segment_num_fifos (fifo_segment_t * fs);
+u32 fifo_segment_num_free_fifos (fifo_segment_t * fs, u32 fifo_size_in_bytes);
+
+void fifo_segment_main_init (fifo_segment_main_t * sm, u64 baseva,
+			     u32 timeout_in_seconds);
+
+format_function_t format_fifo_segment;
+format_function_t format_fifo_segment_type;
+
+#endif /* __included_fifo_segment_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index a335519d1e4..eafe497eec1 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -882,7 +882,7 @@ svm_fifo_dequeue_drop_all (svm_fifo_t * f)
 }
 
 int
-svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs)
+svm_fifo_segments (svm_fifo_t * f, svm_fifo_seg_t * fs)
 {
   u32 cursize, head, tail, head_idx;
 
@@ -914,7 +914,7 @@ svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs)
 }
 
 void
-svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs)
+svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_seg_t * fs)
 {
   u32 head, head_idx;
 
diff --git a/src/svm/svm_fifo.h b/src/svm/svm_fifo.h
index 619d6093429..4f2f61939b7 100644
--- a/src/svm/svm_fifo.h
+++ b/src/svm/svm_fifo.h
@@ -67,6 +67,7 @@ typedef enum svm_fifo_flag_
 {
   SVM_FIFO_F_SIZE_UPDATE = 1 << 0,
   SVM_FIFO_F_MULTI_CHUNK = 1 << 1,
+  SVM_FIFO_F_LL_TRACKED = 1 << 2,
 } svm_fifo_flag_t;
 
 typedef struct _svm_fifo
@@ -124,11 +125,11 @@ typedef enum
   SVM_FIFO_FULL = -2,
 } svm_fifo_err_t;
 
-typedef struct svm_fifo_segment_
+typedef struct svm_fifo_seg_
 {
   u8 *data;
   u32 len;
-} svm_fifo_segment_t;
+} svm_fifo_seg_t;
 
 #if SVM_FIFO_TRACE
 #define svm_fifo_trace_add(_f, _s, _l, _t)		\
@@ -352,8 +353,8 @@ int svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here);
 int svm_fifo_peek (svm_fifo_t * f, u32 offset, u32 max_bytes, u8 * copy_here);
 int svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes);
 void svm_fifo_dequeue_drop_all (svm_fifo_t * f);
-int svm_fifo_segments (svm_fifo_t * f, svm_fifo_segment_t * fs);
-void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_segment_t * fs);
+int svm_fifo_segments (svm_fifo_t * f, svm_fifo_seg_t * fs);
+void svm_fifo_segments_free (svm_fifo_t * f, svm_fifo_seg_t * fs);
 void svm_fifo_init_pointers (svm_fifo_t * f, u32 head, u32 tail);
 void svm_fifo_clone (svm_fifo_t * df, svm_fifo_t * sf);
 void svm_fifo_overwrite_head (svm_fifo_t * f, u8 * data, u32 len);
diff --git a/src/svm/svm_fifo_segment.h b/src/svm/svm_fifo_segment.h
deleted file mode 100644
index d4d48093ae6..00000000000
--- a/src/svm/svm_fifo_segment.h
+++ /dev/null
@@ -1,136 +0,0 @@
-/*
- * Copyright (c) 2016-2019 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#ifndef __included_ssvm_fifo_segment_h__
-#define __included_ssvm_fifo_segment_h__
-
-#include <svm/ssvm.h>
-#include <svm/svm_fifo.h>
-#include <vppinfra/lock.h>
-
-typedef enum
-{
-  FIFO_SEGMENT_FREELIST_NONE = -1,
-  FIFO_SEGMENT_RX_FREELIST = 0,
-  FIFO_SEGMENT_TX_FREELIST,
-  FIFO_SEGMENT_N_FREELISTS
-} svm_fifo_segment_freelist_t;
-
-#define FIFO_SEGMENT_MIN_FIFO_SIZE 4096
-#define FIFO_SEGMENT_MAX_FIFO_SIZE (2 << 30)	/* 2GB max fifo size */
-#define FIFO_SEGMENT_ALLOC_CHUNK_SIZE 32	/* Allocation quantum */
-
-#define FIFO_SEGMENT_F_IS_PREALLOCATED	(1 << 0)
-#define FIFO_SEGMENT_F_WILL_DELETE	(1 << 1)
-
-typedef struct
-{
-  svm_fifo_t *fifos;		/**< Linked list of active RX fifos */
-  svm_fifo_t **free_fifos;	/**< Freelists, by fifo size  */
-  u32 n_active_fifos;		/**< Number of active fifos */
-  u8 flags;			/**< Segment flags */
-} svm_fifo_segment_header_t;
-
-typedef struct
-{
-  ssvm_private_t ssvm;
-  svm_fifo_segment_header_t *h;
-} svm_fifo_segment_private_t;
-
-typedef struct
-{
-  volatile u32 lock;
-
-  /** pool of segments */
-  svm_fifo_segment_private_t *segments;
-  /* Where to put the next one */
-  u64 next_baseva;
-  u32 timeout_in_seconds;
-} svm_fifo_segment_main_t;
-
-typedef struct
-{
-  ssvm_segment_type_t segment_type;
-  char *segment_name;
-  u32 segment_size;
-  u32 *new_segment_indices;
-  int memfd_fd;
-} svm_fifo_segment_create_args_t;
-
-#define svm_fifo_segment_flags(_seg) _seg->h->flags
-
-static inline svm_fifo_segment_private_t *
-svm_fifo_segment_get_segment (svm_fifo_segment_main_t * sm, u32 segment_index)
-{
-  return pool_elt_at_index (sm->segments, segment_index);
-}
-
-static inline u8
-svm_fifo_segment_has_fifos (svm_fifo_segment_private_t * fifo_segment)
-{
-  return fifo_segment->h->fifos != 0;
-}
-
-static inline svm_fifo_t *
-svm_fifo_segment_get_fifo_list (svm_fifo_segment_private_t * fifo_segment)
-{
-  return fifo_segment->h->fifos;
-}
-
-int svm_fifo_segment_init (svm_fifo_segment_private_t * s);
-int svm_fifo_segment_create (svm_fifo_segment_main_t * sm,
-			     svm_fifo_segment_create_args_t * a);
-int svm_fifo_segment_create_process_private (svm_fifo_segment_main_t * sm,
-					     svm_fifo_segment_create_args_t
-					     *);
-void svm_fifo_segment_preallocate_fifo_pairs (svm_fifo_segment_private_t * s,
-					      u32 rx_fifo_size,
-					      u32 tx_fifo_size,
-					      u32 * n_fifo_pairs);
-int svm_fifo_segment_attach (svm_fifo_segment_main_t * sm,
-			     svm_fifo_segment_create_args_t * a);
-void svm_fifo_segment_delete (svm_fifo_segment_main_t * sm,
-			      svm_fifo_segment_private_t * s);
-
-svm_fifo_t *svm_fifo_segment_alloc_fifo (svm_fifo_segment_private_t * s,
-					 u32 data_size_in_bytes,
-					 svm_fifo_segment_freelist_t index);
-void svm_fifo_segment_free_fifo (svm_fifo_segment_private_t * s,
-				 svm_fifo_t * f,
-				 svm_fifo_segment_freelist_t index);
-void svm_fifo_segment_main_init (svm_fifo_segment_main_t * sm, u64 baseva,
-				 u32 timeout_in_seconds);
-u32 svm_fifo_segment_index (svm_fifo_segment_main_t * sm,
-			    svm_fifo_segment_private_t * s);
-u32 svm_fifo_segment_num_fifos (svm_fifo_segment_private_t * fifo_segment);
-u32 svm_fifo_segment_num_free_fifos (svm_fifo_segment_private_t *
-				     fifo_segment, u32 fifo_size_in_bytes);
-void svm_fifo_segment_info (svm_fifo_segment_private_t * seg, char **address,
-			    size_t * size);
-
-svm_fifo_segment_private_t
-  * svm_fifo_segment_segments_pool (svm_fifo_segment_main_t * sm);
-
-format_function_t format_svm_fifo_segment;
-format_function_t format_svm_fifo_segment_type;
-
-#endif /* __included_ssvm_fifo_segment_h__ */
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */
diff --git a/src/tests/vnet/session/quic_echo.c b/src/tests/vnet/session/quic_echo.c
index 4d1288f66d5..7d0cedd1d6b 100644
--- a/src/tests/vnet/session/quic_echo.c
+++ b/src/tests/vnet/session/quic_echo.c
@@ -17,10 +17,10 @@
 #include <signal.h>
 
 #include <vnet/session/application_interface.h>
-#include <svm/svm_fifo_segment.h>
 #include <vlibmemory/api.h>
 
 #include <vpp/api/vpe_msg_enum.h>
+#include <svm/fifo_segment.h>
 
 #define vl_typedefs		/* define message structures */
 #include <vpp/api/vpe_all_api_h.h>
@@ -141,7 +141,7 @@ typedef struct
    * and all other messages are exchanged using shm IPC. */
   u8 use_sock_api;
 
-  svm_fifo_segment_main_t segment_main;
+  fifo_segment_main_t segment_main;
 } echo_main_t;
 
 echo_main_t echo_main;
@@ -290,8 +290,8 @@ application_detach (echo_main_t * em)
 static int
 ssvm_segment_attach (char *name, ssvm_segment_type_t type, int fd)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  svm_fifo_segment_main_t *sm = &echo_main.segment_main;
+  fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &echo_main.segment_main;
   int rv;
 
   clib_memset (a, 0, sizeof (*a));
@@ -301,7 +301,7 @@ ssvm_segment_attach (char *name, ssvm_segment_type_t type, int fd)
   if (type == SSVM_SEGMENT_MEMFD)
     a->memfd_fd = fd;
 
-  if ((rv = svm_fifo_segment_attach (sm, a)))
+  if ((rv = fifo_segment_attach (sm, a)))
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed", name);
       return rv;
@@ -454,15 +454,15 @@ disconnect_from_vpp (echo_main_t * em)
 static void
 vl_api_map_another_segment_t_handler (vl_api_map_another_segment_t * mp)
 {
-  svm_fifo_segment_main_t *sm = &echo_main.segment_main;
-  svm_fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &echo_main.segment_main;
+  fifo_segment_create_args_t _a, *a = &_a;
   int rv;
 
   clib_memset (a, 0, sizeof (*a));
   a->segment_name = (char *) mp->segment_name;
   a->segment_size = mp->segment_size;
   /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (sm, a);
+  rv = fifo_segment_attach (sm, a);
   if (rv)
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed",
@@ -1286,7 +1286,7 @@ main (int argc, char **argv)
 {
   int i_am_server = 1, test_return_packets = 0;
   echo_main_t *em = &echo_main;
-  svm_fifo_segment_main_t *sm = &em->segment_main;
+  fifo_segment_main_t *sm = &em->segment_main;
   unformat_input_t _argv, *a = &_argv;
   u8 *chroot_prefix;
   u8 *uri = 0;
@@ -1309,7 +1309,7 @@ main (int argc, char **argv)
 
   clib_time_init (&em->clib_time);
   init_error_string_table (em);
-  svm_fifo_segment_main_init (sm, HIGH_SEGMENT_BASEVA, 20);
+  fifo_segment_main_init (sm, HIGH_SEGMENT_BASEVA, 20);
   unformat_init_command_line (a, argv);
 
   while (unformat_check_input (a) != UNFORMAT_END_OF_INPUT)
diff --git a/src/tests/vnet/session/tcp_echo.c b/src/tests/vnet/session/tcp_echo.c
index 3fcc285dc11..6c3ce928490 100644
--- a/src/tests/vnet/session/tcp_echo.c
+++ b/src/tests/vnet/session/tcp_echo.c
@@ -17,10 +17,10 @@
 #include <signal.h>
 
 #include <vnet/session/application_interface.h>
-#include <svm/svm_fifo_segment.h>
 #include <vlibmemory/api.h>
 
 #include <vpp/api/vpe_msg_enum.h>
+#include <svm/fifo_segment.h>
 
 #define vl_typedefs		/* define message structures */
 #include <vpp/api/vpe_all_api_h.h>
@@ -141,7 +141,7 @@ typedef struct
    * and all other messages are exchanged using shm IPC. */
   u8 use_sock_api;
 
-  svm_fifo_segment_main_t segment_main;
+  fifo_segment_main_t segment_main;
 } echo_main_t;
 
 echo_main_t echo_main;
@@ -290,8 +290,8 @@ application_detach (echo_main_t * em)
 static int
 ssvm_segment_attach (char *name, ssvm_segment_type_t type, int fd)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
-  svm_fifo_segment_main_t *sm = &echo_main.segment_main;
+  fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &echo_main.segment_main;
   int rv;
 
   clib_memset (a, 0, sizeof (*a));
@@ -301,7 +301,7 @@ ssvm_segment_attach (char *name, ssvm_segment_type_t type, int fd)
   if (type == SSVM_SEGMENT_MEMFD)
     a->memfd_fd = fd;
 
-  if ((rv = svm_fifo_segment_attach (sm, a)))
+  if ((rv = fifo_segment_attach (sm, a)))
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed", name);
       return rv;
@@ -456,15 +456,15 @@ disconnect_from_vpp (echo_main_t * em)
 static void
 vl_api_map_another_segment_t_handler (vl_api_map_another_segment_t * mp)
 {
-  svm_fifo_segment_main_t *sm = &echo_main.segment_main;
-  svm_fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_main_t *sm = &echo_main.segment_main;
+  fifo_segment_create_args_t _a, *a = &_a;
   int rv;
 
   clib_memset (a, 0, sizeof (*a));
   a->segment_name = (char *) mp->segment_name;
   a->segment_size = mp->segment_size;
   /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (sm, a);
+  rv = fifo_segment_attach (sm, a);
   if (rv)
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed",
@@ -1291,7 +1291,7 @@ main (int argc, char **argv)
 {
   int i_am_server = 1, test_return_packets = 0;
   echo_main_t *em = &echo_main;
-  svm_fifo_segment_main_t *sm = &em->segment_main;
+  fifo_segment_main_t *sm = &em->segment_main;
   unformat_input_t _argv, *a = &_argv;
   u8 *chroot_prefix;
   u8 *uri = 0;
@@ -1314,7 +1314,7 @@ main (int argc, char **argv)
 
   clib_time_init (&em->clib_time);
   init_error_string_table (em);
-  svm_fifo_segment_main_init (sm, HIGH_SEGMENT_BASEVA, 20);
+  fifo_segment_main_init (sm, HIGH_SEGMENT_BASEVA, 20);
   unformat_init_command_line (a, argv);
 
   while (unformat_check_input (a) != UNFORMAT_END_OF_INPUT)
diff --git a/src/tests/vnet/session/udp_echo.c b/src/tests/vnet/session/udp_echo.c
index c949d4cbf6d..f1ecca8e926 100644
--- a/src/tests/vnet/session/udp_echo.c
+++ b/src/tests/vnet/session/udp_echo.c
@@ -27,9 +27,9 @@
 #include <vlibapi/api.h>
 #include <vlibmemory/api.h>
 #include <vpp/api/vpe_msg_enum.h>
-#include <svm/svm_fifo_segment.h>
 #include <pthread.h>
 #include <vnet/session/application_interface.h>
+#include <svm/fifo_segment.h>
 
 #define vl_typedefs		/* define message structures */
 #include <vpp/api/vpe_all_api_h.h>
@@ -79,7 +79,7 @@ typedef struct
   uword *session_index_by_vpp_handles;
 
   /* fifo segment */
-  svm_fifo_segment_private_t *seg;
+  fifo_segment_t *seg;
 
   /* intermediate rx buffer */
   u8 *rx_buf;
@@ -121,7 +121,7 @@ typedef struct
   /* VNET_API_ERROR_FOO -> "Foo" hash table */
   uword *error_string_by_error_number;
 
-  svm_fifo_segment_main_t segment_main;
+  fifo_segment_main_t segment_main;
 
   u8 *connect_test_data;
 
@@ -334,9 +334,9 @@ static void
 vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
 					   mp)
 {
-  svm_fifo_segment_create_args_t _a = { 0 }, *a = &_a;
+  fifo_segment_create_args_t _a = { 0 }, *a = &_a;
   udp_echo_main_t *utm = &udp_echo_main;
-  svm_fifo_segment_main_t *sm = &utm->segment_main;
+  fifo_segment_main_t *sm = &utm->segment_main;
   int rv;
 
   if (mp->retval)
@@ -358,7 +358,7 @@ vl_api_application_attach_reply_t_handler (vl_api_application_attach_reply_t *
   ASSERT (mp->app_event_queue_address);
 
   /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (sm, a);
+  rv = fifo_segment_attach (sm, a);
   if (rv)
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed",
@@ -841,24 +841,24 @@ client_test (udp_echo_main_t * utm)
 static void
 vl_api_map_another_segment_t_handler (vl_api_map_another_segment_t * mp)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_create_args_t _a, *a = &_a;
   udp_echo_main_t *utm = &udp_echo_main;
-  svm_fifo_segment_main_t *sm = &utm->segment_main;
-  svm_fifo_segment_private_t *seg;
+  fifo_segment_main_t *sm = &utm->segment_main;
+  fifo_segment_t *seg;
   int rv;
 
   clib_memset (a, 0, sizeof (*a));
   a->segment_name = (char *) mp->segment_name;
   a->segment_size = mp->segment_size;
   /* Attach to the segment vpp created */
-  rv = svm_fifo_segment_attach (sm, a);
+  rv = fifo_segment_attach (sm, a);
   if (rv)
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed",
 		    mp->segment_name);
       return;
     }
-  seg = svm_fifo_segment_get_segment (sm, a->new_segment_indices[0]);
+  seg = fifo_segment_get_segment (sm, a->new_segment_indices[0]);
   clib_warning ("Mapped new segment '%s' size %d", seg->ssvm.name,
 		seg->ssvm.ssvm_size);
   hash_set (utm->segments_table, clib_net_to_host_u64 (mp->segment_handle),
@@ -869,8 +869,8 @@ static void
 vl_api_unmap_segment_t_handler (vl_api_unmap_segment_t * mp)
 {
   udp_echo_main_t *utm = &udp_echo_main;
-  svm_fifo_segment_main_t *sm = &utm->segment_main;
-  svm_fifo_segment_private_t *seg;
+  fifo_segment_main_t *sm = &utm->segment_main;
+  fifo_segment_t *seg;
   uword *seg_indexp;
   u64 segment_handle;
 
@@ -882,8 +882,8 @@ vl_api_unmap_segment_t_handler (vl_api_unmap_segment_t * mp)
       return;
     }
   hash_unset (utm->segments_table, segment_handle);
-  seg = svm_fifo_segment_get_segment (sm, (u32) seg_indexp[0]);
-  svm_fifo_segment_delete (sm, seg);
+  seg = fifo_segment_get_segment (sm, (u32) seg_indexp[0]);
+  fifo_segment_delete (sm, seg);
   clib_warning ("Unmapped segment '%s'", segment_handle);
 }
 
@@ -1127,7 +1127,7 @@ int
 main (int argc, char **argv)
 {
   udp_echo_main_t *utm = &udp_echo_main;
-  svm_fifo_segment_main_t *sm = &utm->segment_main;
+  fifo_segment_main_t *sm = &utm->segment_main;
   u8 *uri = (u8 *) "udp://6.0.1.1/1234";
   unformat_input_t _argv, *a = &_argv;
   int i_am_server = 1;
@@ -1139,7 +1139,7 @@ main (int argc, char **argv)
 
   clib_mem_init_thread_safe (0, 256 << 20);
 
-  svm_fifo_segment_main_init (sm, HIGH_SEGMENT_BASEVA, 20);
+  fifo_segment_main_init (sm, HIGH_SEGMENT_BASEVA, 20);
 
   vec_validate (utm->rx_buf, 128 << 10);
   utm->session_index_by_vpp_handles = hash_create (0, sizeof (uword));
diff --git a/src/vcl/vcl_bapi.c b/src/vcl/vcl_bapi.c
index b9f621d356d..b28398101b3 100644
--- a/src/vcl/vcl_bapi.c
+++ b/src/vcl/vcl_bapi.c
@@ -65,7 +65,7 @@ static int
 vcl_segment_attach (u64 segment_handle, char *name, ssvm_segment_type_t type,
 		    int fd)
 {
-  svm_fifo_segment_create_args_t _a, *a = &_a;
+  fifo_segment_create_args_t _a, *a = &_a;
   int rv;
 
   memset (a, 0, sizeof (*a));
@@ -75,7 +75,7 @@ vcl_segment_attach (u64 segment_handle, char *name, ssvm_segment_type_t type,
   if (type == SSVM_SEGMENT_MEMFD)
     a->memfd_fd = fd;
 
-  if ((rv = svm_fifo_segment_attach (&vcm->segment_main, a)))
+  if ((rv = fifo_segment_attach (&vcm->segment_main, a)))
     {
       clib_warning ("svm_fifo_segment_attach ('%s') failed", name);
       return rv;
@@ -88,15 +88,15 @@ vcl_segment_attach (u64 segment_handle, char *name, ssvm_segment_type_t type,
 static void
 vcl_segment_detach (u64 segment_handle)
 {
-  svm_fifo_segment_main_t *sm = &vcm->segment_main;
-  svm_fifo_segment_private_t *segment;
+  fifo_segment_main_t *sm = &vcm->segment_main;
+  fifo_segment_t *segment;
   u32 segment_index;
 
   segment_index = vcl_segment_table_lookup (segment_handle);
   if (segment_index == (u32) ~ 0)
     return;
-  segment = svm_fifo_segment_get_segment (sm, segment_index);
-  svm_fifo_segment_delete (sm, segment);
+  segment = fifo_segment_get_segment (sm, segment_index);
+  fifo_segment_delete (sm, segment);
   vcl_segment_table_del (segment_handle);
   VDBG (0, "detached segment %u handle %u", segment_index, segment_handle);
 }
diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index 57828cf5b37..8bafa5f74b4 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -325,7 +325,7 @@ typedef struct vppcom_main_t_
   /** Mapped segments table */
   uword *segment_table;
 
-  svm_fifo_segment_main_t segment_main;
+  fifo_segment_main_t segment_main;
 
 #ifdef VCL_ELOG
   /* VPP Event-logger */
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 6668d465fca..1641beee9f6 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -15,10 +15,10 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <svm/svm_fifo_segment.h>
 #include <vcl/vppcom.h>
 #include <vcl/vcl_debug.h>
 #include <vcl/vcl_private.h>
+#include <svm/fifo_segment.h>
 
 __thread uword __vcl_worker_index = ~0;
 
@@ -924,8 +924,8 @@ vppcom_app_create (char *app_name)
   vcm->main_pid = getpid ();
   vcm->app_name = format (0, "%s", app_name);
   vppcom_init_error_string_table ();
-  svm_fifo_segment_main_init (&vcm->segment_main, vcl_cfg->segment_baseva,
-			      20 /* timeout in secs */ );
+  fifo_segment_main_init (&vcm->segment_main, vcl_cfg->segment_baseva,
+			  20 /* timeout in secs */ );
   pool_alloc (vcm->workers, vcl_cfg->max_workers);
   clib_spinlock_init (&vcm->workers_lock);
   clib_rwlock_init (&vcm->segment_table_lock);
@@ -1611,7 +1611,7 @@ vppcom_session_read_segments (uint32_t session_handle,
 	}
     }
 
-  n_read = svm_fifo_segments (rx_fifo, (svm_fifo_segment_t *) ds);
+  n_read = svm_fifo_segments (rx_fifo, (svm_fifo_seg_t *) ds);
   svm_fifo_unset_event (rx_fifo);
 
   return n_read;
@@ -1628,7 +1628,7 @@ vppcom_session_free_segments (uint32_t session_handle,
   if (PREDICT_FALSE (!s || s->is_vep))
     return;
 
-  svm_fifo_segments_free (s->rx_fifo, (svm_fifo_segment_t *) ds);
+  svm_fifo_segments_free (s->rx_fifo, (svm_fifo_seg_t *) ds);
 }
 
 int
diff --git a/src/vnet/session-apps/echo_client.h b/src/vnet/session-apps/echo_client.h
index 81ffcae77dd..68a5921f753 100644
--- a/src/vnet/session-apps/echo_client.h
+++ b/src/vnet/session-apps/echo_client.h
@@ -24,7 +24,6 @@
 
 #include <vppinfra/hash.h>
 #include <vppinfra/error.h>
-#include <svm/svm_fifo_segment.h>
 #include <vnet/session/session.h>
 #include <vnet/session/application_interface.h>
 
diff --git a/src/vnet/session-apps/proxy.h b/src/vnet/session-apps/proxy.h
index 6a24358ad65..9b80b3d1105 100644
--- a/src/vnet/session-apps/proxy.h
+++ b/src/vnet/session-apps/proxy.h
@@ -23,7 +23,6 @@
 
 #include <vppinfra/hash.h>
 #include <vppinfra/error.h>
-#include <svm/svm_fifo_segment.h>
 #include <vnet/session/session.h>
 #include <vnet/session/application_interface.h>
 
diff --git a/src/vnet/session/application.c b/src/vnet/session/application.c
index 82b6dfef534..69cc87c9575 100644
--- a/src/vnet/session/application.c
+++ b/src/vnet/session/application.c
@@ -504,7 +504,7 @@ static int
 application_alloc_and_init (app_init_args_t * a)
 {
   ssvm_segment_type_t seg_type = SSVM_SEGMENT_MEMFD;
-  segment_manager_properties_t *props;
+  segment_manager_props_t *props;
   vl_api_registration_t *reg;
   application_t *app;
   u64 *options;
@@ -553,7 +553,7 @@ application_alloc_and_init (app_init_args_t * a)
     app->flags |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
 
   props = application_segment_manager_properties (app);
-  segment_manager_properties_init (props);
+  segment_manager_props_init (props);
   props->segment_size = options[APP_OPTIONS_ADD_SEGMENT_SIZE];
   props->prealloc_fifos = options[APP_OPTIONS_PREALLOC_FIFO_PAIRS];
   if (options[APP_OPTIONS_ADD_SEGMENT_SIZE])
@@ -719,7 +719,7 @@ application_alloc_worker_and_init (application_t * app, app_worker_t ** wrk)
   /*
    * Setup first segment manager
    */
-  sm = segment_manager_new ();
+  sm = segment_manager_alloc ();
   sm->app_wrk_index = app_wrk->wrk_index;
 
   if ((rv = segment_manager_init (sm, app->sm_properties.segment_size,
@@ -746,7 +746,7 @@ application_alloc_worker_and_init (application_t * app, app_worker_t ** wrk)
 int
 vnet_app_worker_add_del (vnet_app_worker_add_del_args_t * a)
 {
-  svm_fifo_segment_private_t *fs;
+  fifo_segment_t *fs;
   app_worker_map_t *wrk_map;
   app_worker_t *app_wrk;
   segment_manager_t *sm;
@@ -838,7 +838,7 @@ app_name_from_api_index (u32 api_client_index)
 int
 vnet_application_attach (vnet_app_attach_args_t * a)
 {
-  svm_fifo_segment_private_t *fs;
+  fifo_segment_t *fs;
   application_t *app = 0;
   app_worker_t *app_wrk;
   segment_manager_t *sm;
@@ -1313,13 +1313,13 @@ application_remove_proxy (application_t * app)
   /* *INDENT-ON* */
 }
 
-segment_manager_properties_t *
+segment_manager_props_t *
 application_segment_manager_properties (application_t * app)
 {
   return &app->sm_properties;
 }
 
-segment_manager_properties_t *
+segment_manager_props_t *
 application_get_segment_manager_properties (u32 app_index)
 {
   application_t *app = application_get (app_index);
@@ -1404,7 +1404,7 @@ format_application (u8 * s, va_list * args)
 {
   application_t *app = va_arg (*args, application_t *);
   CLIB_UNUSED (int verbose) = va_arg (*args, int);
-  segment_manager_properties_t *props;
+  segment_manager_props_t *props;
   const u8 *app_ns_name, *app_name;
   app_worker_map_t *wrk_map;
   app_worker_t *app_wrk;
diff --git a/src/vnet/session/application.h b/src/vnet/session/application.h
index 0cf97a75742..4485b743589 100644
--- a/src/vnet/session/application.h
+++ b/src/vnet/session/application.h
@@ -92,7 +92,7 @@ typedef struct application_
   session_cb_vft_t cb_fns;
 
   /** Segment manager properties. Shared by all segment managers */
-  segment_manager_properties_t sm_properties;
+  segment_manager_props_t sm_properties;
 
   /** Pool of mappings that keep track of workers associated to this app */
   app_worker_map_t *worker_maps;
@@ -197,10 +197,10 @@ u8 application_has_global_scope (application_t * app);
 void application_setup_proxy (application_t * app);
 void application_remove_proxy (application_t * app);
 
-segment_manager_properties_t *application_get_segment_manager_properties (u32
-									  app_index);
+segment_manager_props_t *application_get_segment_manager_properties (u32
+								     app_index);
 
-segment_manager_properties_t
+segment_manager_props_t
   * application_segment_manager_properties (application_t * app);
 
 /*
diff --git a/src/vnet/session/application_interface.h b/src/vnet/session/application_interface.h
index 3e6abdbec86..aa1a3f30877 100644
--- a/src/vnet/session/application_interface.h
+++ b/src/vnet/session/application_interface.h
@@ -17,9 +17,9 @@
 
 #include <vlibmemory/api.h>
 #include <svm/message_queue.h>
-#include <svm/svm_fifo_segment.h>
 #include <vnet/session/session_types.h>
 #include <vnet/tls/tls_test.h>
+#include <svm/fifo_segment.h>
 
 typedef struct _stream_session_cb_vft
 {
diff --git a/src/vnet/session/application_local.c b/src/vnet/session/application_local.c
index d2edd54512a..f868e1964cc 100644
--- a/src/vnet/session/application_local.c
+++ b/src/vnet/session/application_local.c
@@ -91,10 +91,10 @@ ct_session_endpoint (session_t * ll, session_endpoint_t * sep)
 int
 ct_session_connect_notify (session_t * ss)
 {
-  svm_fifo_segment_private_t *seg;
   ct_connection_t *sct, *cct;
   app_worker_t *client_wrk;
   segment_manager_t *sm;
+  fifo_segment_t *seg;
   u64 segment_handle;
   int is_fail = 0;
   session_t *cs;
@@ -167,11 +167,11 @@ ct_init_local_session (app_worker_t * client_wrk, app_worker_t * server_wrk,
 		       ct_connection_t * ct, session_t * ls, session_t * ll)
 {
   u32 round_rx_fifo_sz, round_tx_fifo_sz, sm_index, seg_size;
-  segment_manager_properties_t *props;
-  svm_fifo_segment_private_t *seg;
+  segment_manager_props_t *props;
   application_t *server;
   segment_manager_t *sm;
   u32 margin = 16 << 10;
+  fifo_segment_t *seg;
   u64 segment_handle;
   int seg_index, rv;
 
diff --git a/src/vnet/session/application_worker.c b/src/vnet/session/application_worker.c
index 3cc84e84f1a..d98c437ec84 100644
--- a/src/vnet/session/application_worker.c
+++ b/src/vnet/session/application_worker.c
@@ -95,7 +95,7 @@ app_worker_free (app_worker_t * app_wrk)
       sm = segment_manager_get (app_wrk->connects_seg_manager);
       sm->app_wrk_index = SEGMENT_MANAGER_INVALID_APP_INDEX;
       sm->first_is_protected = 0;
-      segment_manager_init_del (sm);
+      segment_manager_init_free (sm);
     }
 
   /* If first segment manager is used by a listener */
@@ -108,7 +108,7 @@ app_worker_free (app_worker_t * app_wrk)
       /* .. and has no fifos, e.g. it might be used for redirected sessions,
        * remove it */
       if (!segment_manager_has_fifos (sm))
-	segment_manager_del (sm);
+	segment_manager_free (sm);
     }
 
   pool_put (app_workers, app_wrk);
@@ -140,7 +140,7 @@ app_worker_alloc_segment_manager (app_worker_t * app_wrk)
       return sm;
     }
 
-  sm = segment_manager_new ();
+  sm = segment_manager_alloc ();
   sm->app_wrk_index = app_wrk->wrk_index;
 
   return sm;
@@ -238,7 +238,7 @@ app_worker_stop_listen_session (app_worker_t * app_wrk, session_t * ls)
     }
   else
     {
-      segment_manager_init_del (sm);
+      segment_manager_init_free (sm);
     }
   hash_unset (app_wrk->listeners_table, handle);
 }
@@ -698,63 +698,20 @@ format_app_worker (u8 * s, va_list * args)
 void
 app_worker_format_connects (app_worker_t * app_wrk, int verbose)
 {
-  svm_fifo_segment_private_t *fifo_segment;
-  vlib_main_t *vm = vlib_get_main ();
   segment_manager_t *sm;
-  const u8 *app_name;
-  u8 *s = 0;
 
   /* Header */
   if (!app_wrk)
     {
-      if (verbose)
-	vlib_cli_output (vm, "%-40s%-20s%-15s%-10s", "Connection", "App",
-			 "API Client", "SegManager");
-      else
-	vlib_cli_output (vm, "%-40s%-20s", "Connection", "App");
+      segment_manager_format_sessions (0, verbose);
       return;
     }
 
   if (app_wrk->connects_seg_manager == (u32) ~ 0)
     return;
 
-  app_name = application_name_from_index (app_wrk->app_index);
-
-  /* Across all fifo segments */
   sm = segment_manager_get (app_wrk->connects_seg_manager);
-
-  /* *INDENT-OFF* */
-  segment_manager_foreach_segment_w_lock (fifo_segment, sm, ({
-    svm_fifo_t *fifo;
-    u8 *str;
-
-    fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
-    while (fifo)
-      {
-        u32 session_index, thread_index;
-        session_t *session;
-
-        session_index = fifo->master_session_index;
-        thread_index = fifo->master_thread_index;
-
-        session = session_get (session_index, thread_index);
-        str = format (0, "%U", format_session, session, verbose);
-
-        if (verbose)
-          s = format (s, "%-40s%-20s%-15u%-10u", str, app_name,
-                      app_wrk->api_client_index, app_wrk->connects_seg_manager);
-        else
-          s = format (s, "%-40s%-20s", str, app_name);
-
-        vlib_cli_output (vm, "%v", s);
-        vec_reset_length (s);
-        vec_free (str);
-
-        fifo = fifo->next;
-      }
-    vec_free (s);
-  }));
-  /* *INDENT-ON* */
+  segment_manager_format_sessions (sm, verbose);
 }
 
 /*
diff --git a/src/vnet/session/segment_manager.c b/src/vnet/session/segment_manager.c
index 2437f99098b..47c7f563542 100644
--- a/src/vnet/session/segment_manager.c
+++ b/src/vnet/session/segment_manager.c
@@ -17,34 +17,43 @@
 #include <vnet/session/session.h>
 #include <vnet/session/application.h>
 
-segment_manager_main_t segment_manager_main;
+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 */
 
-/**
- * Counter used to build segment names
- */
-static u32 segment_name_counter = 0;
+  /*
+   * Configuration
+   */
+  u32 default_fifo_size;		/**< default rx/tx fifo size */
+  u32 default_segment_size;		/**< default fifo segment size */
+  u32 default_app_mq_size;		/**< default app msg q size */
+} segment_manager_main_t;
 
-/**
- * Default fifo and segment size. TODO config.
- */
-static u32 default_fifo_size = 1 << 12;
-static u32 default_segment_size = 1 << 20;
-static u32 default_app_evt_queue_size = 128;
+static segment_manager_main_t sm_main;
 
-segment_manager_properties_t *
+#define segment_manager_foreach_segment_w_lock(VAR, SM, BODY)		\
+do {									\
+    clib_rwlock_reader_lock (&(SM)->segments_rwlock);			\
+    pool_foreach((VAR), ((SM)->segments), (BODY));			\
+    clib_rwlock_reader_unlock (&(SM)->segments_rwlock);			\
+} while (0)
+
+static segment_manager_props_t *
 segment_manager_properties_get (segment_manager_t * sm)
 {
   app_worker_t *app_wrk = app_worker_get (sm->app_wrk_index);
   return application_get_segment_manager_properties (app_wrk->app_index);
 }
 
-segment_manager_properties_t *
-segment_manager_properties_init (segment_manager_properties_t * props)
+segment_manager_props_t *
+segment_manager_props_init (segment_manager_props_t * props)
 {
-  props->add_segment_size = default_segment_size;
-  props->rx_fifo_size = default_fifo_size;
-  props->tx_fifo_size = default_fifo_size;
-  props->evt_q_size = default_app_evt_queue_size;
+  props->add_segment_size = sm_main.default_segment_size;
+  props->rx_fifo_size = sm_main.default_fifo_size;
+  props->tx_fifo_size = sm_main.default_fifo_size;
+  props->evt_q_size = sm_main.default_app_mq_size;
   return props;
 }
 
@@ -61,20 +70,103 @@ segment_manager_app_detach (segment_manager_t * sm)
 }
 
 always_inline u32
-segment_manager_segment_index (segment_manager_t * sm,
-			       svm_fifo_segment_private_t * seg)
+segment_manager_segment_index (segment_manager_t * sm, fifo_segment_t * seg)
 {
   return (seg - sm->segments);
 }
 
 /**
+ * Adds segment to segment manager's pool
+ *
+ * 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, u32 segment_size)
+{
+  segment_manager_main_t *smm = &sm_main;
+  u32 rnd_margin = 128 << 10, fs_index = ~0, page_size;
+  uword baseva = (uword) ~ 0ULL, alloc_size;
+  segment_manager_props_t *props;
+  fifo_segment_t *fs;
+  u8 *seg_name;
+  int rv;
+
+  props = segment_manager_properties_get (sm);
+
+  /* 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;
+    }
+
+  /*
+   * Allocate fifo segment and lock if needed
+   */
+  if (vlib_num_workers ())
+    clib_rwlock_writer_lock (&sm->segments_rwlock);
+
+  pool_get_zero (sm->segments, fs);
+
+  /*
+   * Initialize ssvm segment and svm fifo private header
+   */
+  segment_size = segment_size ? segment_size : props->add_segment_size;
+  page_size = clib_mem_get_page_size ();
+  segment_size = (segment_size + page_size - 1) & ~(page_size - 1);
+  if (props->segment_type != SSVM_SEGMENT_PRIVATE)
+    {
+      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;
+	}
+    }
+  else
+    seg_name = format (0, "%s%c", "process-private-segment", 0);
+
+  fs->ssvm.ssvm_size = segment_size;
+  fs->ssvm.name = seg_name;
+  fs->ssvm.requested_va = baseva;
+
+  if ((rv = ssvm_master_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;
+    }
+
+  fifo_segment_init (fs);
+
+  /*
+   * Save segment index before dropping lock, if any held
+   */
+  fs_index = fs - sm->segments;
+
+done:
+
+  if (vlib_num_workers ())
+    clib_rwlock_writer_unlock (&sm->segments_rwlock);
+
+  return fs_index;
+}
+
+/**
  * Remove segment without lock
  */
 void
-segment_manager_del_segment (segment_manager_t * sm,
-			     svm_fifo_segment_private_t * fs)
+segment_manager_del_segment (segment_manager_t * sm, fifo_segment_t * fs)
 {
-  segment_manager_main_t *smm = &segment_manager_main;
+  segment_manager_main_t *smm = &sm_main;
 
   if (ssvm_type (&fs->ssvm) != SSVM_SEGMENT_PRIVATE)
     {
@@ -103,12 +195,12 @@ segment_manager_del_segment (segment_manager_t * sm,
 static inline void
 segment_manager_lock_and_del_segment (segment_manager_t * sm, u32 fs_index)
 {
-  svm_fifo_segment_private_t *fs;
+  fifo_segment_t *fs;
   u8 is_prealloc;
 
   clib_rwlock_writer_lock (&sm->segments_rwlock);
   fs = segment_manager_get_segment (sm, fs_index);
-  is_prealloc = svm_fifo_segment_flags (fs) & FIFO_SEGMENT_F_IS_PREALLOCATED;
+  is_prealloc = fifo_segment_flags (fs) & FIFO_SEGMENT_F_IS_PREALLOCATED;
   if (is_prealloc && !segment_manager_app_detached (sm))
     {
       clib_rwlock_writer_unlock (&sm->segments_rwlock);
@@ -122,7 +214,7 @@ segment_manager_lock_and_del_segment (segment_manager_t * sm, u32 fs_index)
 /**
  * Reads a segment from the segment manager's pool without lock
  */
-svm_fifo_segment_private_t *
+fifo_segment_t *
 segment_manager_get_segment (segment_manager_t * sm, u32 segment_index)
 {
   return pool_elt_at_index (sm->segments, segment_index);
@@ -130,13 +222,13 @@ segment_manager_get_segment (segment_manager_t * sm, u32 segment_index)
 
 u64
 segment_manager_segment_handle (segment_manager_t * sm,
-				svm_fifo_segment_private_t * segment)
+				fifo_segment_t * segment)
 {
   u32 segment_index = segment_manager_segment_index (sm, segment);
   return (((u64) segment_manager_index (sm) << 32) | segment_index);
 }
 
-void
+static void
 segment_manager_parse_segment_handle (u64 segment_handle, u32 * sm_index,
 				      u32 * segment_index)
 {
@@ -144,7 +236,14 @@ segment_manager_parse_segment_handle (u64 segment_handle, u32 * sm_index,
   *segment_index = segment_handle & 0xFFFFFFFF;
 }
 
-svm_fifo_segment_private_t *
+u64
+segment_manager_make_segment_handle (u32 segment_manager_index,
+				     u32 segment_index)
+{
+  return (((u64) segment_manager_index << 32) | segment_index);
+}
+
+fifo_segment_t *
 segment_manager_get_segment_w_handle (u64 segment_handle)
 {
   u32 sm_index, segment_index;
@@ -165,7 +264,7 @@ segment_manager_get_segment_w_handle (u64 segment_handle)
  * @ref segment_manager_segment_reader_unlock once it finishes working with
  * the segment.
  */
-svm_fifo_segment_private_t *
+fifo_segment_t *
 segment_manager_get_segment_w_lock (segment_manager_t * sm, u32 segment_index)
 {
   clib_rwlock_reader_lock (&sm->segments_rwlock);
@@ -185,98 +284,13 @@ segment_manager_segment_writer_unlock (segment_manager_t * sm)
   clib_rwlock_writer_unlock (&sm->segments_rwlock);
 }
 
-/**
- * Adds segment to segment manager's pool
- *
- * 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, u32 segment_size)
-{
-  segment_manager_main_t *smm = &segment_manager_main;
-  u32 rnd_margin = 128 << 10, seg_index = ~0, page_size;
-  segment_manager_properties_t *props;
-  uword baseva = (uword) ~ 0ULL, alloc_size;
-  svm_fifo_segment_private_t *seg;
-  u8 *seg_name;
-  int rv;
-
-  props = segment_manager_properties_get (sm);
-
-  /* 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;
-    }
-
-  /*
-   * Allocate fifo segment and lock if needed
-   */
-  if (vlib_num_workers ())
-    clib_rwlock_writer_lock (&sm->segments_rwlock);
-
-  pool_get_zero (sm->segments, seg);
-
-  /*
-   * Initialize ssvm segment and svm fifo private header
-   */
-  segment_size = segment_size ? segment_size : props->add_segment_size;
-  page_size = clib_mem_get_page_size ();
-  segment_size = (segment_size + page_size - 1) & ~(page_size - 1);
-  if (props->segment_type != SSVM_SEGMENT_PRIVATE)
-    {
-      seg_name = format (0, "%d-%d%c", getpid (), segment_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, seg);
-	  goto done;
-	}
-    }
-  else
-    seg_name = format (0, "%s%c", "process-private-segment", 0);
-
-  seg->ssvm.ssvm_size = segment_size;
-  seg->ssvm.name = seg_name;
-  seg->ssvm.requested_va = baseva;
-
-  if ((rv = ssvm_master_init (&seg->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, seg);
-      goto done;
-    }
-
-  svm_fifo_segment_init (seg);
-
-  /*
-   * Save segment index before dropping lock, if any held
-   */
-  seg_index = seg - sm->segments;
-
-done:
-
-  if (vlib_num_workers ())
-    clib_rwlock_writer_unlock (&sm->segments_rwlock);
-
-  return seg_index;
-}
-
 segment_manager_t *
-segment_manager_new ()
+segment_manager_alloc (void)
 {
-  segment_manager_main_t *smm = &segment_manager_main;
+  segment_manager_main_t *smm = &sm_main;
   segment_manager_t *sm;
-  pool_get (smm->segment_managers, sm);
-  clib_memset (sm, 0, sizeof (*sm));
+
+  pool_get_zero (smm->segment_managers, sm);
   clib_rwlock_init (&sm->segments_rwlock);
   return sm;
 }
@@ -292,13 +306,13 @@ segment_manager_init (segment_manager_t * sm, u32 first_seg_size,
   u32 rx_fifo_size, tx_fifo_size, pair_size;
   u32 rx_rounded_data_size, tx_rounded_data_size;
   u64 approx_total_size, max_seg_size = ((u64) 1 << 32) - (128 << 10);
-  segment_manager_properties_t *props;
-  svm_fifo_segment_private_t *segment;
+  segment_manager_props_t *props;
+  fifo_segment_t *segment;
   u32 approx_segment_count;
   int seg_index, i;
 
   props = segment_manager_properties_get (sm);
-  first_seg_size = clib_max (first_seg_size, default_segment_size);
+  first_seg_size = clib_max (first_seg_size, sm_main.default_segment_size);
 
   if (prealloc_fifo_pairs)
     {
@@ -330,11 +344,11 @@ segment_manager_init (segment_manager_t * sm, u32 first_seg_size,
 	  if (i == 0)
 	    sm->event_queue = segment_manager_alloc_queue (segment, props);
 
-	  svm_fifo_segment_preallocate_fifo_pairs (segment,
-						   props->rx_fifo_size,
-						   props->tx_fifo_size,
-						   &prealloc_fifo_pairs);
-	  svm_fifo_segment_flags (segment) = FIFO_SEGMENT_F_IS_PREALLOCATED;
+	  fifo_segment_preallocate_fifo_pairs (segment,
+					       props->rx_fifo_size,
+					       props->tx_fifo_size,
+					       &prealloc_fifo_pairs);
+	  fifo_segment_flags (segment) = FIFO_SEGMENT_F_IS_PREALLOCATED;
 	  if (prealloc_fifo_pairs == 0)
 	    break;
 	}
@@ -354,22 +368,87 @@ segment_manager_init (segment_manager_t * sm, u32 first_seg_size,
   return 0;
 }
 
+/**
+ * Cleanup segment manager.
+ */
+void
+segment_manager_free (segment_manager_t * sm)
+{
+  segment_manager_main_t *smm = &sm_main;
+  fifo_segment_t *fifo_segment;
+
+  ASSERT (!segment_manager_has_fifos (sm)
+	  && segment_manager_app_detached (sm));
+
+  /* If we have empty preallocated segments that haven't been removed, remove
+   * them now. Apart from that, the first segment in the first segment manager
+   * is not removed when all fifos are removed. It can only be removed when
+   * the manager is explicitly deleted/detached by the app. */
+  clib_rwlock_writer_lock (&sm->segments_rwlock);
+
+  /* *INDENT-OFF* */
+  pool_foreach (fifo_segment, sm->segments, ({
+    segment_manager_del_segment (sm, fifo_segment);
+  }));
+  /* *INDENT-ON* */
+
+  clib_rwlock_writer_unlock (&sm->segments_rwlock);
+
+  clib_rwlock_free (&sm->segments_rwlock);
+  if (CLIB_DEBUG)
+    clib_memset (sm, 0xfe, sizeof (*sm));
+  pool_put (smm->segment_managers, sm);
+}
+
+void
+segment_manager_init_free (segment_manager_t * sm)
+{
+  segment_manager_app_detach (sm);
+  if (segment_manager_has_fifos (sm))
+    segment_manager_del_sessions (sm);
+  else
+    {
+      ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
+      segment_manager_free (sm);
+    }
+}
+
+segment_manager_t *
+segment_manager_get (u32 index)
+{
+  return pool_elt_at_index (sm_main.segment_managers, index);
+}
+
+segment_manager_t *
+segment_manager_get_if_valid (u32 index)
+{
+  if (pool_is_free_index (sm_main.segment_managers, index))
+    return 0;
+  return pool_elt_at_index (sm_main.segment_managers, index);
+}
+
+u32
+segment_manager_index (segment_manager_t * sm)
+{
+  return sm - sm_main.segment_managers;
+}
+
 u8
 segment_manager_has_fifos (segment_manager_t * sm)
 {
-  svm_fifo_segment_private_t *seg;
+  fifo_segment_t *seg;
   u8 first = 1;
 
   /* *INDENT-OFF* */
   segment_manager_foreach_segment_w_lock (seg, sm, ({
-    if (CLIB_DEBUG && !first && !svm_fifo_segment_has_fifos (seg)
-	&& !(svm_fifo_segment_flags (seg) & FIFO_SEGMENT_F_IS_PREALLOCATED))
+    if (CLIB_DEBUG && !first && !fifo_segment_has_fifos (seg)
+	&& !(fifo_segment_flags (seg) & FIFO_SEGMENT_F_IS_PREALLOCATED))
       {
 	clib_warning ("segment %d has no fifos!",
 	              segment_manager_segment_index (sm, seg));
 	first = 0;
       }
-    if (svm_fifo_segment_has_fifos (seg))
+    if (fifo_segment_has_fifos (seg))
       {
 	segment_manager_segment_reader_unlock (sm);
 	return 1;
@@ -386,7 +465,7 @@ segment_manager_has_fifos (segment_manager_t * sm)
 void
 segment_manager_del_sessions (segment_manager_t * sm)
 {
-  svm_fifo_segment_private_t *fifo_segment;
+  fifo_segment_t *fifo_segment;
   session_handle_t *handles = 0, *handle;
   session_t *session;
   svm_fifo_t *fifo;
@@ -396,7 +475,7 @@ segment_manager_del_sessions (segment_manager_t * sm)
   /* Across all fifo segments used by the server */
   /* *INDENT-OFF* */
   segment_manager_foreach_segment_w_lock (fifo_segment, sm, ({
-    fifo = svm_fifo_segment_get_fifo_list (fifo_segment);
+    fifo = fifo_segment_get_fifo_list (fifo_segment);
 
     /*
      * Remove any residual sessions from the session lookup table
@@ -422,75 +501,25 @@ segment_manager_del_sessions (segment_manager_t * sm)
     session_close (session_get_from_handle (*handle));
 }
 
-/**
- * Removes segment manager.
- *
- * Since the fifos allocated in the segment keep backpointers to the sessions
- * prior to removing the segment, we call session disconnect. This
- * subsequently propagates into transport.
- */
-void
-segment_manager_del (segment_manager_t * sm)
-{
-  segment_manager_main_t *smm = &segment_manager_main;
-  svm_fifo_segment_private_t *fifo_segment;
-
-  ASSERT (!segment_manager_has_fifos (sm)
-	  && segment_manager_app_detached (sm));
-
-  /* If we have empty preallocated segments that haven't been removed, remove
-   * them now. Apart from that, the first segment in the first segment manager
-   * is not removed when all fifos are removed. It can only be removed when
-   * the manager is explicitly deleted/detached by the app. */
-  clib_rwlock_writer_lock (&sm->segments_rwlock);
-
-  /* *INDENT-OFF* */
-  pool_foreach (fifo_segment, sm->segments, ({
-    segment_manager_del_segment (sm, fifo_segment);
-  }));
-  /* *INDENT-ON* */
-
-  clib_rwlock_writer_unlock (&sm->segments_rwlock);
-
-  clib_rwlock_free (&sm->segments_rwlock);
-  if (CLIB_DEBUG)
-    clib_memset (sm, 0xfe, sizeof (*sm));
-  pool_put (smm->segment_managers, sm);
-}
-
-void
-segment_manager_init_del (segment_manager_t * sm)
-{
-  segment_manager_app_detach (sm);
-  if (segment_manager_has_fifos (sm))
-    segment_manager_del_sessions (sm);
-  else
-    {
-      ASSERT (!sm->first_is_protected || segment_manager_app_detached (sm));
-      segment_manager_del (sm);
-    }
-}
-
 int
-segment_manager_try_alloc_fifos (svm_fifo_segment_private_t * fifo_segment,
+segment_manager_try_alloc_fifos (fifo_segment_t * fifo_segment,
 				 u32 rx_fifo_size, u32 tx_fifo_size,
 				 svm_fifo_t ** rx_fifo, svm_fifo_t ** tx_fifo)
 {
-  rx_fifo_size = clib_max (rx_fifo_size, default_fifo_size);
-  *rx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, rx_fifo_size,
-					  FIFO_SEGMENT_RX_FREELIST);
+  rx_fifo_size = clib_max (rx_fifo_size, sm_main.default_fifo_size);
+  *rx_fifo = fifo_segment_alloc_fifo (fifo_segment, rx_fifo_size,
+				      FIFO_SEGMENT_RX_FIFO);
 
-  tx_fifo_size = clib_max (tx_fifo_size, default_fifo_size);
-  *tx_fifo = svm_fifo_segment_alloc_fifo (fifo_segment, tx_fifo_size,
-					  FIFO_SEGMENT_TX_FREELIST);
+  tx_fifo_size = clib_max (tx_fifo_size, sm_main.default_fifo_size);
+  *tx_fifo = fifo_segment_alloc_fifo (fifo_segment, tx_fifo_size,
+				      FIFO_SEGMENT_TX_FIFO);
 
   if (*rx_fifo == 0)
     {
       /* This would be very odd, but handle it... */
       if (*tx_fifo != 0)
 	{
-	  svm_fifo_segment_free_fifo (fifo_segment, *tx_fifo,
-				      FIFO_SEGMENT_TX_FREELIST);
+	  fifo_segment_free_fifo (fifo_segment, *tx_fifo);
 	  *tx_fifo = 0;
 	}
       return -1;
@@ -499,8 +528,7 @@ segment_manager_try_alloc_fifos (svm_fifo_segment_private_t * fifo_segment,
     {
       if (*rx_fifo != 0)
 	{
-	  svm_fifo_segment_free_fifo (fifo_segment, *rx_fifo,
-				      FIFO_SEGMENT_RX_FREELIST);
+	  fifo_segment_free_fifo (fifo_segment, *rx_fifo);
 	  *rx_fifo = 0;
 	}
       return -1;
@@ -514,12 +542,12 @@ segment_manager_alloc_session_fifos (segment_manager_t * sm,
 				     svm_fifo_t ** rx_fifo,
 				     svm_fifo_t ** tx_fifo)
 {
-  svm_fifo_segment_private_t *fifo_segment = 0;
   int alloc_fail = 1, rv = 0, new_fs_index;
-  segment_manager_properties_t *props;
-  u32 sm_index, fifo_segment_index;
+  segment_manager_props_t *props;
+  fifo_segment_t *fs = 0;
+  u32 sm_index, fs_index;
   u8 added_a_segment = 0;
-  u64 segment_handle;
+  u64 fs_handle;
 
   props = segment_manager_properties_get (sm);
 
@@ -528,8 +556,8 @@ segment_manager_alloc_session_fifos (segment_manager_t * sm,
    */
 
   /* *INDENT-OFF* */
-  segment_manager_foreach_segment_w_lock (fifo_segment, sm, ({
-    alloc_fail = segment_manager_try_alloc_fifos (fifo_segment,
+  segment_manager_foreach_segment_w_lock (fs, sm, ({
+    alloc_fail = segment_manager_try_alloc_fifos (fs,
                                                   props->rx_fifo_size,
                                                   props->tx_fifo_size,
                                                   rx_fifo, tx_fifo);
@@ -548,18 +576,18 @@ alloc_check:
 
       ASSERT (rx_fifo && tx_fifo);
       sm_index = segment_manager_index (sm);
-      fifo_segment_index = segment_manager_segment_index (sm, fifo_segment);
+      fs_index = segment_manager_segment_index (sm, fs);
       (*tx_fifo)->segment_manager = sm_index;
       (*rx_fifo)->segment_manager = sm_index;
-      (*tx_fifo)->segment_index = fifo_segment_index;
-      (*rx_fifo)->segment_index = fifo_segment_index;
+      (*tx_fifo)->segment_index = fs_index;
+      (*rx_fifo)->segment_index = fs_index;
 
       if (added_a_segment)
 	{
 	  app_worker_t *app_wrk;
-	  segment_handle = segment_manager_segment_handle (sm, fifo_segment);
+	  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, segment_handle);
+	  rv = app_worker_add_segment_notify (app_wrk, fs_handle);
 	}
       /* Drop the lock after app is notified */
       segment_manager_segment_reader_unlock (sm);
@@ -582,9 +610,8 @@ alloc_check:
 	  clib_warning ("Failed to add new segment");
 	  return SESSION_ERROR_SEG_CREATE;
 	}
-      fifo_segment = segment_manager_get_segment_w_lock (sm, new_fs_index);
-      alloc_fail = segment_manager_try_alloc_fifos (fifo_segment,
-						    props->rx_fifo_size,
+      fs = segment_manager_get_segment_w_lock (sm, new_fs_index);
+      alloc_fail = segment_manager_try_alloc_fifos (fs, props->rx_fifo_size,
 						    props->tx_fifo_size,
 						    rx_fifo, tx_fifo);
       added_a_segment = 1;
@@ -600,7 +627,7 @@ alloc_check:
 void
 segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo, svm_fifo_t * tx_fifo)
 {
-  svm_fifo_segment_private_t *fifo_segment;
+  fifo_segment_t *fs;
   segment_manager_t *sm;
   u32 segment_index;
 
@@ -613,11 +640,9 @@ segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo, svm_fifo_t * tx_fifo)
     return;
 
   segment_index = rx_fifo->segment_index;
-  fifo_segment = segment_manager_get_segment_w_lock (sm, segment_index);
-  svm_fifo_segment_free_fifo (fifo_segment, rx_fifo,
-			      FIFO_SEGMENT_RX_FREELIST);
-  svm_fifo_segment_free_fifo (fifo_segment, tx_fifo,
-			      FIFO_SEGMENT_TX_FREELIST);
+  fs = segment_manager_get_segment_w_lock (sm, segment_index);
+  fifo_segment_free_fifo (fs, rx_fifo);
+  fifo_segment_free_fifo (fs, tx_fifo);
 
   /*
    * Try to remove svm segment if it has no fifos. This can be done only if
@@ -625,7 +650,7 @@ segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo, svm_fifo_t * tx_fifo)
    * 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 (!svm_fifo_segment_has_fifos (fifo_segment))
+  if (!fifo_segment_has_fifos (fs))
     {
       segment_manager_segment_reader_unlock (sm);
 
@@ -637,7 +662,7 @@ segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo, svm_fifo_t * tx_fifo)
       if (segment_manager_app_detached (sm)
 	  && !segment_manager_has_fifos (sm))
 	{
-	  segment_manager_del (sm);
+	  segment_manager_free (sm);
 	}
     }
   else
@@ -667,8 +692,8 @@ segment_manager_evt_q_expected_size (u32 q_len)
  * Must be called with lock held
  */
 svm_msg_q_t *
-segment_manager_alloc_queue (svm_fifo_segment_private_t * segment,
-			     segment_manager_properties_t * props)
+segment_manager_alloc_queue (fifo_segment_t * segment,
+			     segment_manager_props_t * props)
 {
   u32 fifo_evt_size, session_evt_size = 256, notif_q_size;
   svm_msg_q_cfg_t _cfg, *cfg = &_cfg;
@@ -700,13 +725,19 @@ segment_manager_alloc_queue (svm_fifo_segment_private_t * segment,
   return q;
 }
 
+svm_msg_q_t *
+segment_manager_event_queue (segment_manager_t * sm)
+{
+  return sm->event_queue;
+}
+
 /**
  * Frees shm queue allocated in the first segment
  */
 void
 segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q)
 {
-  svm_fifo_segment_private_t *segment;
+  fifo_segment_t *segment;
   ssvm_shared_header_t *sh;
   void *oldheap;
 
@@ -727,21 +758,25 @@ segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q)
 void
 segment_manager_main_init (segment_manager_main_init_args_t * a)
 {
-  segment_manager_main_t *sm = &segment_manager_main;
+  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;
+  sm->default_app_mq_size = 128;
 }
 
 static clib_error_t *
 segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
 			 vlib_cli_command_t * cmd)
 {
-  segment_manager_main_t *smm = &segment_manager_main;
-  svm_fifo_segment_private_t *seg;
+  segment_manager_main_t *smm = &sm_main;
+  fifo_segment_t *seg;
   segment_manager_t *sm;
   u8 show_segments = 0, verbose = 0;
   char *address;
@@ -782,15 +817,15 @@ segment_manager_show_fn (vlib_main_t * vm, unformat_input_t * input,
       /* *INDENT-OFF* */
       pool_foreach (sm, smm->segment_managers, ({
 	  segment_manager_foreach_segment_w_lock (seg, sm, ({
-	    svm_fifo_segment_info (seg, &address, &size);
-	    active_fifos = svm_fifo_segment_num_fifos (seg);
-	    free_fifos = svm_fifo_segment_num_free_fifos (seg, ~0 /* size */);
+	    fifo_segment_info (seg, &address, &size);
+	    active_fifos = fifo_segment_num_fifos (seg);
+	    free_fifos = fifo_segment_num_free_fifos (seg, ~0 /* size */);
 	    vlib_cli_output (vm, "%-15v%15U%15llu%15u%15u%15llx",
-			     ssvm_name (&seg->ssvm), format_svm_fifo_segment_type,
+			     ssvm_name (&seg->ssvm), format_fifo_segment_type,
 			     seg, size >> 20ULL, active_fifos, free_fifos,
 			     address);
 	    if (verbose)
-	      vlib_cli_output (vm, "%U", format_svm_fifo_segment, seg, verbose);
+	      vlib_cli_output (vm, "%U", format_fifo_segment, seg, verbose);
 	  }));
       }));
       /* *INDENT-ON* */
@@ -808,6 +843,66 @@ VLIB_CLI_COMMAND (segment_manager_show_command, static) =
 };
 /* *INDENT-ON* */
 
+void
+segment_manager_format_sessions (segment_manager_t * sm, int verbose)
+{
+  fifo_segment_t *fifo_segment;
+  vlib_main_t *vm = vlib_get_main ();
+  app_worker_t *app_wrk;
+  const u8 *app_name;
+  u8 *s = 0;
+
+  if (!sm)
+    {
+      if (verbose)
+	vlib_cli_output (vm, "%-40s%-20s%-15s%-10s", "Connection", "App",
+			 "API Client", "SegManager");
+      else
+	vlib_cli_output (vm, "%-40s%-20s", "Connection", "App");
+      return;
+    }
+
+  app_wrk = app_worker_get (sm->app_wrk_index);
+  app_name = application_name_from_index (app_wrk->app_index);
+
+  clib_rwlock_reader_lock (&sm->segments_rwlock);
+
+  /* *INDENT-OFF* */
+  pool_foreach (fifo_segment, sm->segments, ({
+    svm_fifo_t *fifo;
+    u8 *str;
+
+    fifo = fifo_segment_get_fifo_list (fifo_segment);
+    while (fifo)
+      {
+        u32 session_index, thread_index;
+        session_t *session;
+
+        session_index = fifo->master_session_index;
+        thread_index = fifo->master_thread_index;
+
+        session = session_get (session_index, thread_index);
+        str = format (0, "%U", format_session, session, verbose);
+
+        if (verbose)
+          s = format (s, "%-40s%-20s%-15u%-10u", str, app_name,
+                      app_wrk->api_client_index, app_wrk->connects_seg_manager);
+        else
+          s = format (s, "%-40s%-20s", str, app_name);
+
+        vlib_cli_output (vm, "%v", s);
+        vec_reset_length (s);
+        vec_free (str);
+
+        fifo = fifo->next;
+      }
+    vec_free (s);
+  }));
+  /* *INDENT-ON* */
+
+  clib_rwlock_reader_unlock (&sm->segments_rwlock);
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vnet/session/segment_manager.h b/src/vnet/session/segment_manager.h
index 2b6f43feba7..4f30b7a8d2c 100644
--- a/src/vnet/session/segment_manager.h
+++ b/src/vnet/session/segment_manager.h
@@ -15,14 +15,12 @@
 #ifndef SRC_VNET_SESSION_SEGMENT_MANAGER_H_
 #define SRC_VNET_SESSION_SEGMENT_MANAGER_H_
 
-#include <vnet/vnet.h>
-#include <svm/svm_fifo_segment.h>
 #include <svm/message_queue.h>
-#include <vlibmemory/api.h>
 #include <vppinfra/lock.h>
 #include <vppinfra/valloc.h>
+#include <svm/fifo_segment.h>
 
-typedef struct _segment_manager_properties
+typedef struct _segment_manager_props
 {
   u32 rx_fifo_size;			/**< receive fifo size */
   u32 tx_fifo_size;			/**< transmit fifo size */
@@ -35,12 +33,12 @@ typedef struct _segment_manager_properties
   u8 reserved:6;			/**< reserved flags */
   ssvm_segment_type_t segment_type;	/**< seg type: if set to SSVM_N_TYPES,
 					     private segments are used */
-} segment_manager_properties_t;
+} segment_manager_props_t;
 
 typedef struct _segment_manager
 {
   /** Pool of segments allocated by this manager */
-  svm_fifo_segment_private_t *segments;
+  fifo_segment_t *segments;
 
   /** rwlock that protects the segments pool */
   clib_rwlock_t segments_rwlock;
@@ -61,25 +59,6 @@ typedef struct _segment_manager
   svm_msg_q_t *event_queue;
 } segment_manager_t;
 
-#define segment_manager_foreach_segment_w_lock(VAR, SM, BODY)		\
-do {									\
-    clib_rwlock_reader_lock (&(SM)->segments_rwlock);			\
-    pool_foreach((VAR), ((SM)->segments), (BODY));			\
-    clib_rwlock_reader_unlock (&(SM)->segments_rwlock);			\
-} while (0)
-
-typedef struct segment_manager_main_
-{
-  /** Pool of segment managers */
-  segment_manager_t *segment_managers;
-
-  /** Virtual address allocator */
-  clib_valloc_main_t va_allocator;
-
-} segment_manager_main_t;
-
-extern segment_manager_main_t segment_manager_main;
-
 typedef struct segment_manager_main_init_args_
 {
   u64 baseva;
@@ -88,86 +67,78 @@ typedef struct segment_manager_main_init_args_
 
 #define SEGMENT_MANAGER_INVALID_APP_INDEX ((u32) ~0)
 
-/** Pool of segment managers */
-extern segment_manager_t *segment_managers;
-
-always_inline segment_manager_t *
-segment_manager_get (u32 index)
-{
-  return pool_elt_at_index (segment_manager_main.segment_managers, index);
-}
-
-always_inline segment_manager_t *
-segment_manager_get_if_valid (u32 index)
-{
-  if (pool_is_free_index (segment_manager_main.segment_managers, index))
-    return 0;
-  return pool_elt_at_index (segment_manager_main.segment_managers, index);
-}
-
-always_inline u32
-segment_manager_index (segment_manager_t * sm)
-{
-  return sm - segment_manager_main.segment_managers;
-}
-
-always_inline svm_msg_q_t *
-segment_manager_event_queue (segment_manager_t * sm)
-{
-  return sm->event_queue;
-}
-
-always_inline u64
-segment_manager_make_segment_handle (u32 segment_manager_index,
-				     u32 segment_index)
-{
-  return (((u64) segment_manager_index << 32) | segment_index);
-}
-
-u64 segment_manager_segment_handle (segment_manager_t * sm,
-				    svm_fifo_segment_private_t * segment);
-
-segment_manager_t *segment_manager_new ();
+segment_manager_t *segment_manager_alloc (void);
 int segment_manager_init (segment_manager_t * sm, u32 first_seg_size,
 			  u32 prealloc_fifo_pairs);
 
-svm_fifo_segment_private_t *segment_manager_get_segment (segment_manager_t *,
-							 u32 segment_index);
-svm_fifo_segment_private_t *segment_manager_get_segment_w_handle (u64);
-svm_fifo_segment_private_t
-  * segment_manager_get_segment_w_lock (segment_manager_t * sm,
-					u32 segment_index);
+/**
+ * Cleanup segment manager
+ *
+ * @param sm	segment manager to be freed
+ */
+void segment_manager_free (segment_manager_t * sm);
+
+/**
+ * Initiate segment manager cleanup
+ *
+ * @param sm	segment manager to be freed
+ */
+void segment_manager_init_free (segment_manager_t * sm);
+segment_manager_t *segment_manager_get (u32 index);
+segment_manager_t *segment_manager_get_if_valid (u32 index);
+u32 segment_manager_index (segment_manager_t * sm);
+
 int segment_manager_add_segment (segment_manager_t * sm, u32 segment_size);
 void segment_manager_del_segment (segment_manager_t * sm,
-				  svm_fifo_segment_private_t * fs);
+				  fifo_segment_t * fs);
+fifo_segment_t *segment_manager_get_segment (segment_manager_t * sm,
+					     u32 segment_index);
+fifo_segment_t *segment_manager_get_segment_w_handle (u64 sh);
+fifo_segment_t *segment_manager_get_segment_w_lock (segment_manager_t *,
+						    u32 segment_index);
+int segment_manager_add_first_segment (segment_manager_t * sm,
+				       u32 segment_size);
+u64 segment_manager_make_segment_handle (u32 segment_manager_index,
+					 u32 segment_index);
+u64 segment_manager_segment_handle (segment_manager_t * sm,
+				    fifo_segment_t * segment);
 void segment_manager_segment_reader_unlock (segment_manager_t * sm);
 void segment_manager_segment_writer_unlock (segment_manager_t * sm);
 
-int segment_manager_add_first_segment (segment_manager_t * sm,
-				       u32 segment_size);
-void segment_manager_del_sessions (segment_manager_t * sm);
-void segment_manager_del (segment_manager_t * sm);
-void segment_manager_init_del (segment_manager_t * sm);
-u8 segment_manager_has_fifos (segment_manager_t * sm);
 int segment_manager_alloc_session_fifos (segment_manager_t * sm,
-					 svm_fifo_t ** server_rx_fifo,
-					 svm_fifo_t ** server_tx_fifo);
-int segment_manager_try_alloc_fifos (svm_fifo_segment_private_t * fs,
+					 svm_fifo_t ** rx_fifo,
+					 svm_fifo_t ** tx_fifo);
+int segment_manager_try_alloc_fifos (fifo_segment_t * fs,
 				     u32 rx_fifo_size, u32 tx_fifo_size,
 				     svm_fifo_t ** rx_fifo,
 				     svm_fifo_t ** tx_fifo);
 void segment_manager_dealloc_fifos (svm_fifo_t * rx_fifo,
 				    svm_fifo_t * tx_fifo);
-u32 segment_manager_evt_q_expected_size (u32 q_size);
-svm_msg_q_t *segment_manager_alloc_queue (svm_fifo_segment_private_t * fs,
-					  segment_manager_properties_t *
-					  props);
+u8 segment_manager_has_fifos (segment_manager_t * sm);
+
+svm_msg_q_t *segment_manager_alloc_queue (fifo_segment_t * fs,
+					  segment_manager_props_t * props);
 void segment_manager_dealloc_queue (segment_manager_t * sm, svm_queue_t * q);
+svm_msg_q_t *segment_manager_event_queue (segment_manager_t * sm);
+u32 segment_manager_evt_q_expected_size (u32 q_size);
+
 void segment_manager_app_detach (segment_manager_t * sm);
 
+/**
+ * Cleanup segment manager sessions
+ *
+ * Initiates disconnects for all sessions 'owned' by a segment manager by
+ * leveraging the backpointers that fifos keep.
+ *
+ * @param sm	segment manager whose sessions are to be disconnected
+ */
+void segment_manager_del_sessions (segment_manager_t * sm);
+void segment_manager_format_sessions (segment_manager_t * sm, int verbose);
+
 void segment_manager_main_init (segment_manager_main_init_args_t * a);
-segment_manager_properties_t
-  * segment_manager_properties_init (segment_manager_properties_t * sm);
+
+segment_manager_props_t *segment_manager_props_init (segment_manager_props_t *
+						     sm);
 
 #endif /* SRC_VNET_SESSION_SEGMENT_MANAGER_H_ */
 /*
diff --git a/src/vnet/session/session_api.c b/src/vnet/session/session_api.c
index 0a7781f2876..83af125946e 100755
--- a/src/vnet/session/session_api.c
+++ b/src/vnet/session/session_api.c
@@ -83,8 +83,8 @@ send_add_segment_callback (u32 api_client_index, u64 segment_handle)
 {
   int fds[SESSION_N_FD_TYPE], n_fds = 0;
   vl_api_map_another_segment_t *mp;
-  svm_fifo_segment_private_t *fs;
   vl_api_registration_t *reg;
+  fifo_segment_t *fs;
   ssvm_private_t *sp;
   u8 fd_flags = 0;