X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fsvm%2Ffifo_segment.c;h=0c3a79a613b009db039d181e26ba4e2607885552;hb=b462418890240b2e38dbf522f9dd0196b79e0fa8;hp=a5ffd4af2ed0d9ea0d1ae1f975323cecccbcaaae;hpb=8c4fa01d1360cd5315e671de96dfeff7dae246f5;p=vpp.git

diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index a5ffd4af2ed..0c3a79a613b 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -14,6 +14,37 @@
  */
 
 #include <svm/fifo_segment.h>
+#include <vppinfra/mem.h>
+
+static inline void *
+fsh_alloc_aligned (fifo_segment_header_t *fsh, uword size, uword align)
+{
+  uword cur_pos, cur_pos_align, new_pos;
+
+  cur_pos = clib_atomic_load_relax_n (&fsh->byte_index);
+  cur_pos_align = round_pow2_u64 (cur_pos, align);
+  size = round_pow2_u64 (size, align);
+  new_pos = cur_pos_align + size;
+
+  if (new_pos >= fsh->max_byte_index)
+    return 0;
+
+  while (!clib_atomic_cmp_and_swap_acq_relax (&fsh->byte_index, &cur_pos,
+					      &new_pos, 1 /* weak */))
+    {
+      cur_pos_align = round_pow2_u64 (cur_pos, align);
+      new_pos = cur_pos_align + size;
+      if (new_pos >= fsh->max_byte_index)
+	return 0;
+    }
+  return uword_to_pointer ((u8 *) fsh + cur_pos_align, void *);
+}
+
+static inline void *
+fsh_alloc (fifo_segment_header_t *fsh, uword size)
+{
+  return fsh_alloc_aligned (fsh, size, 8);
+}
 
 static inline fifo_segment_slice_t *
 fsh_slice_get (fifo_segment_header_t * fsh, u32 slice_index)
@@ -21,55 +52,35 @@ fsh_slice_get (fifo_segment_header_t * fsh, u32 slice_index)
   return &fsh->slices[slice_index];
 }
 
+static inline fifo_slice_private_t *
+fs_slice_private_get (fifo_segment_t *fs, u32 slice_index)
+{
+  ASSERT (slice_index < fs->n_slices);
+  return &fs->slices[slice_index];
+}
+
 static char *fifo_segment_mem_status_strings[] = {
 #define _(sym,str) str,
   foreach_segment_mem_status
 #undef _
 };
 
-/**
- * Fifo segment free space
- *
- * Queries the underlying memory manager, dlmalloc, for free space. Since this
- * ends up walking the internal data structures, it should not be called
- * indiscriminately.
- *
- * @param fs		fifo segment
- * @return		number of free bytes
- */
-static uword
-fsh_free_space (fifo_segment_header_t * fsh)
-{
-  return clib_mem_get_heap_free_space (fsh->ssvm_sh->heap);
-}
-
-static inline void
-fsh_free_bytes_sub (fifo_segment_header_t * fsh, int size)
-{
-  clib_atomic_fetch_sub_rel (&fsh->n_free_bytes, size);
-}
-
 static inline uword
 fsh_n_free_bytes (fifo_segment_header_t * fsh)
 {
-  uword n_free = clib_atomic_load_relax_n (&fsh->n_free_bytes);
-  return n_free > fsh->n_reserved_bytes ? n_free - fsh->n_reserved_bytes : 0;
-}
-
-static inline void
-fsh_update_free_bytes (fifo_segment_header_t * fsh)
-{
-  clib_atomic_store_rel_n (&fsh->n_free_bytes, fsh_free_space (fsh));
+  uword cur_pos = clib_atomic_load_relax_n (&fsh->byte_index);
+  ASSERT (fsh->max_byte_index > cur_pos);
+  return fsh->max_byte_index - cur_pos;
 }
 
 static inline void
-fsh_cached_bytes_add (fifo_segment_header_t * fsh, int size)
+fsh_cached_bytes_add (fifo_segment_header_t * fsh, uword size)
 {
   clib_atomic_fetch_add_rel (&fsh->n_cached_bytes, size);
 }
 
 static inline void
-fsh_cached_bytes_sub (fifo_segment_header_t * fsh, int size)
+fsh_cached_bytes_sub (fifo_segment_header_t * fsh, uword size)
 {
   clib_atomic_fetch_sub_rel (&fsh->n_cached_bytes, size);
 }
@@ -116,21 +127,120 @@ fsh_virtual_mem_update (fifo_segment_header_t * fsh, u32 slice_index,
   fss->virtual_mem += n_bytes;
 }
 
+static inline void
+fss_chunk_freelist_lock (fifo_segment_slice_t *fss)
+{
+  u32 free = 0;
+  while (!clib_atomic_cmp_and_swap_acq_relax_n (&fss->chunk_lock, &free, 1, 0))
+    {
+      /* atomic load limits number of compare_exchange executions */
+      while (clib_atomic_load_relax_n (&fss->chunk_lock))
+	CLIB_PAUSE ();
+      /* on failure, compare_exchange writes (*p)->lock into free */
+      free = 0;
+    }
+}
+
+static inline void
+fss_chunk_freelist_unlock (fifo_segment_slice_t *fss)
+{
+  /* Make sure all reads/writes are complete before releasing the lock */
+  clib_atomic_release (&fss->chunk_lock);
+}
+
+static inline int
+fss_chunk_fl_index_is_valid (fifo_segment_slice_t * fss, u32 fl_index)
+{
+  return (fl_index < FS_CHUNK_VEC_LEN);
+}
+
 static void
-fsh_check_mem (fifo_segment_header_t * fsh)
+fss_chunk_free_list_push (fifo_segment_header_t *fsh,
+			  fifo_segment_slice_t *fss, u32 fl_index,
+			  svm_fifo_chunk_t *c)
 {
-  uword thresh;
+  fss_chunk_freelist_lock (fss);
+  c->next = fss->free_chunks[fl_index];
+  fss->free_chunks[fl_index] = fs_chunk_sptr (fsh, c);
+  fss_chunk_freelist_unlock (fss);
+}
 
-  if (fsh->flags & FIFO_SEGMENT_F_MEM_LIMIT)
-    return;
+static void
+fss_chunk_free_list_push_list (fifo_segment_header_t *fsh,
+			       fifo_segment_slice_t *fss, u32 fl_index,
+			       svm_fifo_chunk_t *head, svm_fifo_chunk_t *tail)
+{
+  fss_chunk_freelist_lock (fss);
+  tail->next = fss->free_chunks[fl_index];
+  fss->free_chunks[fl_index] = fs_chunk_sptr (fsh, head);
+  fss_chunk_freelist_unlock (fss);
+}
 
-  thresh = clib_max (0.01 * fsh->ssvm_sh->ssvm_size,
-		     2 * fsh->n_reserved_bytes);
-  if (fsh->n_free_bytes > thresh)
-    return;
+static svm_fifo_chunk_t *
+fss_chunk_free_list_pop (fifo_segment_header_t *fsh, fifo_segment_slice_t *fss,
+			 u32 fl_index)
+{
+  svm_fifo_chunk_t *c;
+
+  ASSERT (fss_chunk_fl_index_is_valid (fss, fl_index));
 
-  fsh->flags |= FIFO_SEGMENT_F_MEM_LIMIT;
-  fsh_update_free_bytes (fsh);
+  fss_chunk_freelist_lock (fss);
+
+  if (!fss->free_chunks[fl_index])
+    {
+      fss_chunk_freelist_unlock (fss);
+      return 0;
+    }
+
+  c = fs_chunk_ptr (fsh, fss->free_chunks[fl_index]);
+  fss->free_chunks[fl_index] = c->next;
+
+  fss_chunk_freelist_unlock (fss);
+
+  return c;
+}
+
+static inline void
+pfss_fifo_add_active_list (fifo_slice_private_t *pfss, svm_fifo_t *f)
+{
+  if (pfss->active_fifos)
+    {
+      pfss->active_fifos->prev = f;
+      f->next = pfss->active_fifos;
+    }
+  pfss->active_fifos = f;
+}
+
+static inline void
+pfss_fifo_del_active_list (fifo_slice_private_t *pfss, svm_fifo_t *f)
+{
+  if (f->flags & SVM_FIFO_F_LL_TRACKED)
+    {
+      if (f->prev)
+	f->prev->next = f->next;
+      else
+	pfss->active_fifos = f->next;
+      if (f->next)
+	f->next->prev = f->prev;
+    }
+}
+
+static inline uword
+fss_fl_chunk_bytes (fifo_segment_slice_t * fss)
+{
+  return clib_atomic_load_relax_n (&fss->n_fl_chunk_bytes);
+}
+
+static inline void
+fss_fl_chunk_bytes_add (fifo_segment_slice_t * fss, uword size)
+{
+  clib_atomic_fetch_add_relax (&fss->n_fl_chunk_bytes, size);
+}
+
+static inline void
+fss_fl_chunk_bytes_sub (fifo_segment_slice_t * fss, uword size)
+{
+  clib_atomic_fetch_sub_relax (&fss->n_fl_chunk_bytes, size);
 }
 
 /**
@@ -139,54 +249,42 @@ fsh_check_mem (fifo_segment_header_t * fsh)
 int
 fifo_segment_init (fifo_segment_t * fs)
 {
+  u32 align = 8, offset = 2 * 4096, slices_sz, i;
+  uword max_fifo, seg_start, seg_sz;
   fifo_segment_header_t *fsh;
-  fifo_segment_slice_t *fss;
   ssvm_shared_header_t *sh;
-  u32 max_chunk_sz;
-  uword max_fifo;
-  void *oldheap;
-  int i;
+  void *seg_data;
 
+  /* TODO remove ssvm heap entirely */
   sh = fs->ssvm.sh;
-  oldheap = ssvm_push_heap (sh);
 
-  /*
-   * Manually align the fifo segment header to sizeof(uword) = 8 bytes.
-   * Long story made short: the "process-private" fifo segment
-   * is allocated from the main heap, not mmapped. dlmalloc
-   * only guarantees 4-byte alignment, and on aarch64
-   * the fsh can end up 4-byte but not 8-byte aligned.
-   * That eventually causes the atomic op in fifo_segment_update_free_bytes
-   * to backfire.
-   */
-  fsh = clib_mem_alloc_aligned (sizeof (*fsh), sizeof (uword));
-  clib_memset (fsh, 0, sizeof (*fsh));
-  fs->h = sh->opaque[0] = fsh;
+  seg_data = (u8 *) sh + offset;
+  seg_sz = sh->ssvm_size - offset;
+
   fs->n_slices = clib_max (fs->n_slices, 1);
+  slices_sz = sizeof (fifo_segment_slice_t) * fs->n_slices;
+
+  seg_start = round_pow2_u64 (pointer_to_uword (seg_data), align);
+  fsh = uword_to_pointer (seg_start, void *);
+  memset (fsh, 0, sizeof (*fsh) + slices_sz);
 
-  fsh->ssvm_sh = fs->ssvm.sh;
+  fsh->byte_index = sizeof (*fsh) + slices_sz;
+  fsh->max_byte_index = seg_sz;
   fsh->n_slices = fs->n_slices;
-  max_fifo = clib_min ((fsh_free_space (fsh) - 4096) / 2,
-		       FIFO_SEGMENT_MAX_FIFO_SIZE);
-  fsh->max_log2_chunk_size = max_log2 (max_fifo);
+  max_fifo = clib_min ((seg_sz - slices_sz) / 2, FIFO_SEGMENT_MAX_FIFO_SIZE);
+  fsh->max_log2_fifo_size = min_log2 (max_fifo);
+  fsh->n_cached_bytes = 0;
+  fsh->n_reserved_bytes = fsh->byte_index;
+  ASSERT (fsh->max_byte_index <= sh->ssvm_size - offset);
 
-  fsh->slices = clib_mem_alloc (sizeof (*fss) * fs->n_slices);
-  clib_memset (fsh->slices, 0, sizeof (*fss) * fs->n_slices);
-  max_chunk_sz = fsh->max_log2_chunk_size - FIFO_SEGMENT_MIN_LOG2_FIFO_SIZE;
+  fs->max_byte_index = fsh->max_byte_index;
+  fs->h = sh->opaque[0] = fsh;
 
+  vec_validate (fs->slices, fs->n_slices - 1);
   for (i = 0; i < fs->n_slices; i++)
-    {
-      fss = fsh_slice_get (fsh, i);
-      vec_validate_init_empty (fss->free_chunks, max_chunk_sz, 0);
-      vec_validate_init_empty (fss->num_chunks, max_chunk_sz, 0);
-      clib_spinlock_init (&fss->chunk_lock);
-    }
+    fs->slices[i].fifos =
+      clib_mem_bulk_init (sizeof (svm_fifo_t), CLIB_CACHE_LINE_BYTES, 32);
 
-  ssvm_pop_heap (oldheap);
-
-  fsh->n_free_bytes = fsh_free_space (fsh);
-  fsh->n_cached_bytes = 0;
-  fsh->n_reserved_bytes = clib_min (0.01 * fsh->n_free_bytes, 256 << 10);
   sh->ready = 1;
   return (0);
 }
@@ -231,6 +329,7 @@ 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)
 {
+  fifo_segment_header_t *fsh;
   fifo_segment_t *fs;
   int rv;
 
@@ -252,8 +351,18 @@ fifo_segment_attach (fifo_segment_main_t * sm, fifo_segment_create_args_t * a)
     }
 
   /* Fish the segment header */
-  fs->h = fs->ssvm.sh->opaque[0];
+  fsh = fs->h = fs->ssvm.sh->opaque[0];
 
+  /* Probably a segment without fifos */
+  if (!fsh)
+    goto done;
+
+  fs->max_byte_index = fsh->max_byte_index;
+  vec_validate (fs->slices, 0);
+  fs->slices[0].fifos =
+    clib_mem_bulk_init (sizeof (svm_fifo_t), CLIB_CACHE_LINE_BYTES, 32);
+
+done:
   vec_add1 (a->new_segment_indices, fs - sm->segments);
   return (0);
 }
@@ -261,6 +370,7 @@ 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 * s)
 {
+  fifo_segment_cleanup (s);
   ssvm_delete (&s->ssvm);
   clib_memset (s, 0xfe, sizeof (*s));
   pool_put (sm->segments, s);
@@ -298,7 +408,8 @@ fs_freelist_for_size (u32 size)
 {
   if (PREDICT_FALSE (size < FIFO_SEGMENT_MIN_FIFO_SIZE))
     return 0;
-  return max_log2 (size) - FIFO_SEGMENT_MIN_LOG2_FIFO_SIZE;
+  return clib_min (max_log2 (size) - FIFO_SEGMENT_MIN_LOG2_FIFO_SIZE,
+		   FS_CHUNK_VEC_LEN - 1);
 }
 
 static inline u32
@@ -314,32 +425,8 @@ fs_chunk_size_is_valid (fifo_segment_header_t * fsh, 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 <= (1ULL << fsh->max_log2_chunk_size);
-}
-
-static svm_fifo_t *
-fs_try_alloc_fifo_freelist (fifo_segment_slice_t * fss, u32 fl_index)
-{
-  svm_fifo_chunk_t *c;
-  svm_fifo_t *f;
-
-  f = fss->free_fifos;
-  c = fss->free_chunks[fl_index];
-
-  if (!f || !c)
-    return 0;
-
-  fss->free_fifos = f->next;
-  fss->free_chunks[fl_index] = c->next;
-  c->next = 0;
-  c->start_byte = 0;
-  memset (f, 0, sizeof (*f));
-  f->start_chunk = c;
-  f->end_chunk = c;
-
-  fss->n_fl_chunk_bytes -= fs_freelist_index_to_size (fl_index);
-  return f;
+  return size >= FIFO_SEGMENT_MIN_FIFO_SIZE &&
+	 size <= (1ULL << fsh->max_log2_fifo_size);
 }
 
 svm_fifo_chunk_t *
@@ -357,11 +444,10 @@ fs_try_alloc_multi_chunk (fifo_segment_header_t * fsh,
 
   while (req_bytes)
     {
-      c = fss->free_chunks[fl_index];
+      c = fss_chunk_free_list_pop (fsh, fss, fl_index);
       if (c)
 	{
-	  fss->free_chunks[fl_index] = c->next;
-	  c->next = first;
+	  c->next = fs_chunk_sptr (fsh, first);
 	  first = c;
 	  n_alloc += fl_size;
 	  req_bytes -= clib_min (fl_size, req_bytes);
@@ -371,28 +457,29 @@ fs_try_alloc_multi_chunk (fifo_segment_header_t * fsh,
 	  /* Failed to allocate with smaller chunks */
 	  if (fl_index == 0)
 	    {
-	      /* free all chunks if any allocated */
+	      /* Free all chunks if any allocated */
 	      c = first;
 	      while (c)
 		{
 		  fl_index = fs_freelist_for_size (c->length);
-		  fl_size = fs_freelist_index_to_size (fl_index);
-		  next = c->next;
-		  c->next = fss->free_chunks[fl_index];
-		  fss->free_chunks[fl_index] = c;
-		  fss->n_fl_chunk_bytes += fl_size;
+		  next = fs_chunk_ptr (fsh, c->next);
+		  fss_chunk_free_list_push (fsh, fss, fl_index, c);
 		  c = next;
 		}
 	      n_alloc = 0;
 	      first = 0;
-	      fl_index = fs_freelist_for_size (data_bytes);
-	      if (fss->free_chunks[fl_index + 1])
+	      /* As last attempt, try allocating a chunk larger than
+	       * the requested size, if possible */
+	      fl_index = fs_freelist_for_size (data_bytes) + 1;
+	      if (!fss_chunk_fl_index_is_valid (fss, fl_index))
+		return 0;
+	      first = fss_chunk_free_list_pop (fsh, fss, fl_index);
+	      if (first)
 		{
-		  fl_index += 1;
-		  fl_size = fs_freelist_index_to_size (fl_index);
-		  continue;
+		  first->next = 0;
+		  n_alloc = fs_freelist_index_to_size (fl_index);
+		  goto done;
 		}
-
 	      return 0;
 	    }
 	  fl_index -= 1;
@@ -400,100 +487,40 @@ fs_try_alloc_multi_chunk (fifo_segment_header_t * fsh,
 	}
     }
 
-  fss->n_fl_chunk_bytes -= n_alloc;
+done:
+  fss_fl_chunk_bytes_sub (fss, n_alloc);
   fsh_cached_bytes_sub (fsh, n_alloc);
   return first;
 }
 
-static svm_fifo_t *
-fs_try_alloc_fifo_freelist_multi_chunk (fifo_segment_header_t * fsh,
-					fifo_segment_slice_t * fss,
-					u32 data_bytes)
+static int
+fsh_try_alloc_fifo_hdr_batch (fifo_segment_header_t * fsh,
+			      fifo_segment_slice_t * fss, u32 batch_size)
 {
-  svm_fifo_chunk_t *c, *first = 0, *last = 0, *next;
-  u32 fl_index, fl_size, n_alloc = 0;
-  svm_fifo_t *f;
+  svm_fifo_shared_t *f;
+  uword size;
+  u8 *fmem;
+  int i;
 
-  f = fss->free_fifos;
-  if (!f)
-    {
-      if (PREDICT_FALSE (fsh_n_free_bytes (fsh) < sizeof (svm_fifo_t)))
-	return 0;
+  ASSERT (batch_size != 0);
 
-      void *oldheap = ssvm_push_heap (fsh->ssvm_sh);
-      f = clib_mem_alloc_aligned_or_null (sizeof (*f), CLIB_CACHE_LINE_BYTES);
-      ssvm_pop_heap (oldheap);
-      if (!f)
-	return 0;
-      memset (f, 0, sizeof (*f));
-      fsh_free_bytes_sub (fsh, sizeof (*f));
-    }
-  else
-    {
-      fss->free_fifos = f->next;
-    }
+  size = (uword) sizeof (*f) * batch_size;
 
-  fl_index = fs_freelist_for_size (data_bytes);
-  if (fl_index > 0)
-    fl_index -= 1;
-
-  fl_size = fs_freelist_index_to_size (fl_index);
+  fmem = fsh_alloc_aligned (fsh, size, CLIB_CACHE_LINE_BYTES);
+  if (fmem == 0)
+    return -1;
 
-  while (data_bytes)
+  /* Carve fifo hdr space */
+  for (i = 0; i < batch_size; i++)
     {
-      c = fss->free_chunks[fl_index];
-      if (c)
-	{
-	  fss->free_chunks[fl_index] = c->next;
-	  if (!last)
-	    last = c;
-	  c->next = first;
-	  first = c;
-	  n_alloc += fl_size;
-	  data_bytes -= clib_min (fl_size, data_bytes);
-	}
-      else
-	{
-	  /* Failed to allocate with smaller chunks */
-	  if (fl_index == 0)
-	    {
-	      /* free all chunks if any allocated */
-	      c = first;
-	      while (c)
-		{
-		  fl_index = fs_freelist_for_size (c->length);
-		  fl_size = fs_freelist_index_to_size (fl_index);
-		  next = c->next;
-		  c->next = fss->free_chunks[fl_index];
-		  fss->free_chunks[fl_index] = c;
-		  fss->n_fl_chunk_bytes += fl_size;
-		  n_alloc -= fl_size;
-		  data_bytes += fl_size;
-		  c = next;
-		}
-	      first = last = 0;
-	      fl_index = fs_freelist_for_size (data_bytes);
-	      if (fss->free_chunks[fl_index + 1])
-		{
-		  fl_index += 1;
-		  fl_size = fs_freelist_index_to_size (fl_index);
-		  continue;
-		}
-
-	      f->next = fss->free_fifos;
-	      fss->free_fifos = f;
-	      return 0;
-	    }
-	  fl_index -= 1;
-	  fl_size = fl_size >> 1;
-	}
+      f = (svm_fifo_shared_t *) fmem;
+      memset (f, 0, sizeof (*f));
+      f->next = fss->free_fifos;
+      fss->free_fifos = f;
+      fmem += sizeof (*f);
     }
 
-  f->start_chunk = first;
-  f->end_chunk = last;
-  fss->n_fl_chunk_bytes -= n_alloc;
-  fsh_cached_bytes_sub (fsh, n_alloc);
-  return f;
+  return 0;
 }
 
 static int
@@ -501,43 +528,38 @@ fsh_try_alloc_chunk_batch (fifo_segment_header_t * fsh,
 			   fifo_segment_slice_t * fss,
 			   u32 fl_index, u32 batch_size)
 {
+  svm_fifo_chunk_t *c, *head = 0, *tail;
+  uword size, total_chunk_bytes;
   u32 rounded_data_size;
-  svm_fifo_chunk_t *c;
-  void *oldheap;
-  uword size;
   u8 *cmem;
   int i;
 
+  ASSERT (batch_size != 0);
+
   rounded_data_size = fs_freelist_index_to_size (fl_index);
+  total_chunk_bytes = (uword) batch_size *rounded_data_size;
   size = (uword) (sizeof (*c) + rounded_data_size) * batch_size;
 
-  oldheap = ssvm_push_heap (fsh->ssvm_sh);
-  cmem = clib_mem_alloc_aligned_at_offset (size, CLIB_CACHE_LINE_BYTES,
-					   0 /* align_offset */ ,
-					   0 /* os_out_of_memory */ );
-  ssvm_pop_heap (oldheap);
-
-  /* Out of space.. */
+  cmem = fsh_alloc_aligned (fsh, size, 8 /* chunk hdr is 24B */);
   if (cmem == 0)
     return -1;
 
   /* Carve fifo + chunk space */
+  tail = c = (svm_fifo_chunk_t *) cmem;
   for (i = 0; i < batch_size; i++)
     {
-      c = (svm_fifo_chunk_t *) cmem;
       c->start_byte = 0;
       c->length = rounded_data_size;
-      c->enq_rb_index = RBTREE_TNIL_INDEX;
-      c->deq_rb_index = RBTREE_TNIL_INDEX;
-      c->next = fss->free_chunks[fl_index];
-      fss->free_chunks[fl_index] = c;
+      c->next = fs_chunk_sptr (fsh, head);
+      head = c;
       cmem += sizeof (*c) + rounded_data_size;
+      c = (svm_fifo_chunk_t *) cmem;
     }
 
+  fss_chunk_free_list_push_list (fsh, fss, fl_index, head, tail);
   fss->num_chunks[fl_index] += batch_size;
-  fss->n_fl_chunk_bytes += batch_size * rounded_data_size;
-  fsh_cached_bytes_add (fsh, batch_size * rounded_data_size);
-  fsh_free_bytes_sub (fsh, size);
+  fss_fl_chunk_bytes_add (fss, total_chunk_bytes);
+  fsh_cached_bytes_add (fsh, total_chunk_bytes);
 
   return 0;
 }
@@ -547,224 +569,142 @@ fs_try_alloc_fifo_batch (fifo_segment_header_t * fsh,
 			 fifo_segment_slice_t * fss,
 			 u32 fl_index, u32 batch_size)
 {
-  u32 hdrs, rounded_data_size;
-  svm_fifo_chunk_t *c;
-  svm_fifo_t *f;
-  void *oldheap;
-  uword size;
-  u8 *fmem;
-  int i;
-
-  rounded_data_size = fs_freelist_index_to_size (fl_index);
-  hdrs = sizeof (*f) + sizeof (*c);
-  size = (uword) (hdrs + rounded_data_size) * batch_size;
-
-  oldheap = ssvm_push_heap (fsh->ssvm_sh);
-  fmem = clib_mem_alloc_aligned_at_offset (size, CLIB_CACHE_LINE_BYTES,
-					   0 /* align_offset */ ,
-					   0 /* os_out_of_memory */ );
-  ssvm_pop_heap (oldheap);
-
-  /* Out of space.. */
-  if (fmem == 0)
-    return -1;
-
-  /* Carve fifo hdr space */
-  for (i = 0; i < batch_size; i++)
-    {
-      f = (svm_fifo_t *) fmem;
-      memset (f, 0, sizeof (*f));
-      f->next = fss->free_fifos;
-      fss->free_fifos = f;
-      fmem += sizeof (*f);
-    }
-
-  /* Carve chunk space */
-  for (i = 0; i < batch_size; i++)
-    {
-      c = (svm_fifo_chunk_t *) fmem;
-      c->start_byte = 0;
-      c->length = rounded_data_size;
-      c->enq_rb_index = RBTREE_TNIL_INDEX;
-      c->deq_rb_index = RBTREE_TNIL_INDEX;
-      c->next = fss->free_chunks[fl_index];
-      fss->free_chunks[fl_index] = c;
-      fmem += sizeof (svm_fifo_chunk_t) + rounded_data_size;
-    }
-
-  fss->num_chunks[fl_index] += batch_size;
-  fss->n_fl_chunk_bytes += batch_size * rounded_data_size;
-  fsh_cached_bytes_add (fsh, batch_size * rounded_data_size);
-  fsh_free_bytes_sub (fsh, size);
-
-  return 0;
+  if (fsh_try_alloc_fifo_hdr_batch (fsh, fss, batch_size))
+    return 0;
+  return fsh_try_alloc_chunk_batch (fsh, fss, fl_index, batch_size);
 }
 
-/**
- * Try to allocate new fifo
- *
- * Tries the following steps in order:
- * - grab fifo and chunk from freelists
- * - batch fifo and chunk allocation
- * - single fifo allocation
- * - grab multiple fifo chunks from freelists
- */
-static svm_fifo_t *
-fs_try_alloc_fifo (fifo_segment_header_t * fsh, fifo_segment_slice_t * fss,
-		   u32 data_bytes)
+static svm_fifo_shared_t *
+fsh_try_alloc_fifo_hdr (fifo_segment_header_t *fsh, fifo_segment_slice_t *fss)
 {
-  u32 fifo_sz, fl_index;
-  svm_fifo_t *f = 0;
-  uword n_free_bytes;
-  u32 min_size;
-
-  min_size = clib_max ((fsh->pct_first_alloc * data_bytes) / 100, 4096);
-  fl_index = fs_freelist_for_size (min_size);
+  svm_fifo_shared_t *f;
 
-  if (fl_index >= vec_len (fss->free_chunks))
-    return 0;
-
-  clib_spinlock_lock (&fss->chunk_lock);
-
-  if (fss->free_fifos && fss->free_chunks[fl_index])
+  if (!fss->free_fifos)
     {
-      f = fs_try_alloc_fifo_freelist (fss, fl_index);
-      if (f)
-	{
-	  fsh_cached_bytes_sub (fsh, fs_freelist_index_to_size (fl_index));
-	  goto done;
-	}
-    }
-
-  fifo_sz = sizeof (svm_fifo_t) + sizeof (svm_fifo_chunk_t);
-  fifo_sz += 1 << max_log2 (min_size);
-  n_free_bytes = fsh_n_free_bytes (fsh);
-
-  if (fifo_sz * FIFO_SEGMENT_ALLOC_BATCH_SIZE < n_free_bytes)
-    {
-      if (!fs_try_alloc_fifo_batch (fsh, fss, fl_index,
-				    FIFO_SEGMENT_ALLOC_BATCH_SIZE))
-	{
-	  f = fs_try_alloc_fifo_freelist (fss, fl_index);
-	  if (f)
-	    {
-	      fsh_cached_bytes_sub (fsh,
-				    fs_freelist_index_to_size (fl_index));
-	      goto done;
-	    }
-	}
-      else
-	{
-	  fsh_check_mem (fsh);
-	  n_free_bytes = fsh_n_free_bytes (fsh);
-	}
-    }
-  if (fifo_sz <= n_free_bytes)
-    {
-      void *oldheap = ssvm_push_heap (fsh->ssvm_sh);
-      f = svm_fifo_alloc (min_size);
-      ssvm_pop_heap (oldheap);
-      if (f)
-	{
-	  clib_atomic_fetch_add_rel (&fss->num_chunks[fl_index], 1);
-	  fsh_free_bytes_sub (fsh, fifo_sz);
-	  goto done;
-	}
-      fsh_check_mem (fsh);
+      if (fsh_try_alloc_fifo_hdr_batch (fsh, fss,
+					FIFO_SEGMENT_ALLOC_BATCH_SIZE))
+	return 0;
     }
-  /* All failed, try to allocate min of data bytes and fifo sz */
-  fifo_sz = clib_min (fifo_sz, data_bytes);
-  if (fifo_sz <= fss->n_fl_chunk_bytes)
-    f = fs_try_alloc_fifo_freelist_multi_chunk (fsh, fss, fifo_sz);
 
-done:
-  clib_spinlock_unlock (&fss->chunk_lock);
-
-  if (f)
-    {
-      f->size = data_bytes;
-      f->fs_hdr = fsh;
-    }
+  f = fss->free_fifos;
+  fss->free_fifos = f->next;
+  memset (f, 0, sizeof (*f));
   return f;
 }
 
-svm_fifo_chunk_t *
-fsh_alloc_chunk (fifo_segment_header_t * fsh, u32 slice_index, u32 chunk_size)
+static svm_fifo_chunk_t *
+fsh_try_alloc_chunk (fifo_segment_header_t * fsh,
+		     fifo_segment_slice_t * fss, u32 data_bytes)
 {
-  fifo_segment_slice_t *fss;
   svm_fifo_chunk_t *c;
-  int fl_index;
-
-  fl_index = fs_freelist_for_size (chunk_size);
-  fss = fsh_slice_get (fsh, slice_index);
-
-  clib_spinlock_lock (&fss->chunk_lock);
+  u32 fl_index;
 
-  ASSERT (vec_len (fss->free_chunks) > fl_index);
-  c = fss->free_chunks[fl_index];
+  fl_index = fs_freelist_for_size (data_bytes);
 
+free_list:
+  c = fss_chunk_free_list_pop (fsh, fss, fl_index);
   if (c)
     {
-      fss->free_chunks[fl_index] = c->next;
       c->next = 0;
-      fss->n_fl_chunk_bytes -= fs_freelist_index_to_size (fl_index);
+      fss_fl_chunk_bytes_sub (fss, fs_freelist_index_to_size (fl_index));
       fsh_cached_bytes_sub (fsh, fs_freelist_index_to_size (fl_index));
     }
   else
     {
-      void *oldheap;
+      u32 chunk_size, batch = FIFO_SEGMENT_ALLOC_BATCH_SIZE;
       uword n_free;
-      u32 batch;
 
       chunk_size = fs_freelist_index_to_size (fl_index);
       n_free = fsh_n_free_bytes (fsh);
 
       if (chunk_size <= n_free)
 	{
-	  oldheap = ssvm_push_heap (fsh->ssvm_sh);
-	  c = svm_fifo_chunk_alloc (chunk_size);
-	  ssvm_pop_heap (oldheap);
-
-	  if (c)
-	    {
-	      clib_atomic_fetch_add_rel (&fss->num_chunks[fl_index], 1);
-	      fsh_free_bytes_sub (fsh, chunk_size + sizeof (*c));
-	      goto done;
-	    }
-
-	  fsh_check_mem (fsh);
-	  n_free = fsh_n_free_bytes (fsh);
+	  batch = chunk_size * batch <= n_free ? batch : 1;
+	  if (!fsh_try_alloc_chunk_batch (fsh, fss, fl_index, batch))
+	    goto free_list;
 	}
-      if (chunk_size <= fss->n_fl_chunk_bytes)
+      /* Failed to allocate larger chunk, try to allocate multi-chunk
+       * that is close to what was actually requested */
+      if (data_bytes <= fss_fl_chunk_bytes (fss))
 	{
-	  c = fs_try_alloc_multi_chunk (fsh, fss, chunk_size);
+	  c = fs_try_alloc_multi_chunk (fsh, fss, data_bytes);
 	  if (c)
 	    goto done;
 	  batch = n_free / FIFO_SEGMENT_MIN_FIFO_SIZE;
 	  if (!batch || fsh_try_alloc_chunk_batch (fsh, fss, 0, batch))
-	    {
-	      fsh_check_mem (fsh);
-	      goto done;
-	    }
+	    goto done;
 	}
-      if (chunk_size <= fss->n_fl_chunk_bytes + n_free)
+      if (data_bytes <= fss_fl_chunk_bytes (fss) + n_free)
 	{
 	  u32 min_size = FIFO_SEGMENT_MIN_FIFO_SIZE;
 
-	  batch = (chunk_size - fss->n_fl_chunk_bytes) / min_size;
+	  batch = (data_bytes - fss_fl_chunk_bytes (fss)) / min_size;
 	  batch = clib_min (batch + 1, n_free / min_size);
 	  if (fsh_try_alloc_chunk_batch (fsh, fss, 0, batch))
-	    {
-	      fsh_check_mem (fsh);
-	      goto done;
-	    }
-	  c = fs_try_alloc_multi_chunk (fsh, fss, chunk_size);
+	    goto done;
+	  c = fs_try_alloc_multi_chunk (fsh, fss, data_bytes);
 	}
     }
 
 done:
 
-  clib_spinlock_unlock (&fss->chunk_lock);
+  return c;
+}
+
+/**
+ * Try to allocate new fifo
+ *
+ * Tries the following steps in order:
+ * - grab fifo and chunk from freelists
+ * - batch fifo and chunk allocation
+ * - single fifo allocation
+ * - grab multiple fifo chunks from freelists
+ */
+static svm_fifo_shared_t *
+fs_try_alloc_fifo (fifo_segment_header_t *fsh, u32 slice_index, u32 data_bytes)
+{
+  fifo_segment_slice_t *fss;
+  u32 fl_index, min_size;
+  svm_fifo_chunk_t *c;
+  svm_fifo_shared_t *sf = 0;
+
+  fss = fsh_slice_get (fsh, slice_index);
+  min_size = clib_max ((fsh->pct_first_alloc * data_bytes) / 100, 4096);
+  fl_index = fs_freelist_for_size (min_size);
+
+  if (!fss_chunk_fl_index_is_valid (fss, fl_index))
+    return 0;
+
+  sf = fsh_try_alloc_fifo_hdr (fsh, fss);
+  if (!sf)
+    return 0;
+
+  c = fsh_try_alloc_chunk (fsh, fss, min_size);
+  if (!c)
+    {
+      sf->next = fss->free_fifos;
+      fss->free_fifos = sf;
+      return 0;
+    }
+
+  sf->start_chunk = fs_chunk_sptr (fsh, c);
+  while (c->next)
+    c = fs_chunk_ptr (fsh, c->next);
+  sf->end_chunk = fs_chunk_sptr (fsh, c);
+  sf->size = data_bytes;
+  sf->slice_index = slice_index;
+
+  return sf;
+}
+
+svm_fifo_chunk_t *
+fsh_alloc_chunk (fifo_segment_header_t * fsh, u32 slice_index, u32 chunk_size)
+{
+  fifo_segment_slice_t *fss;
+  svm_fifo_chunk_t *c;
+
+  fss = fsh_slice_get (fsh, slice_index);
+  c = fsh_try_alloc_chunk (fsh, fss, chunk_size);
 
   return c;
 }
@@ -773,29 +713,21 @@ static void
 fsh_slice_collect_chunks (fifo_segment_header_t * fsh,
 			  fifo_segment_slice_t * fss, svm_fifo_chunk_t * c)
 {
+  u32 n_collect = 0, fl_index;
   svm_fifo_chunk_t *next;
-  int fl_index;
-  u32 n_collect = 0;
-
-  clib_spinlock_lock (&fss->chunk_lock);
 
   while (c)
     {
       CLIB_MEM_UNPOISON (c, sizeof (*c));
-      next = c->next;
+      next = fs_chunk_ptr (fsh, c->next);
       fl_index = fs_freelist_for_size (c->length);
-      c->next = fss->free_chunks[fl_index];
-      c->enq_rb_index = RBTREE_TNIL_INDEX;
-      c->deq_rb_index = RBTREE_TNIL_INDEX;
-      fss->free_chunks[fl_index] = c;
+      fss_chunk_free_list_push (fsh, fss, fl_index, c);
       n_collect += fs_freelist_index_to_size (fl_index);
       c = next;
     }
 
-  fss->n_fl_chunk_bytes += n_collect;
+  fss_fl_chunk_bytes_add (fss, n_collect);
   fsh_cached_bytes_add (fsh, n_collect);
-
-  clib_spinlock_unlock (&fss->chunk_lock);
 }
 
 void
@@ -807,29 +739,40 @@ fsh_collect_chunks (fifo_segment_header_t * fsh, u32 slice_index,
   fsh_slice_collect_chunks (fsh, fss, c);
 }
 
-static inline void
-fss_fifo_add_active_list (fifo_segment_slice_t * fss, svm_fifo_t * f)
+svm_fifo_t *
+fs_fifo_alloc (fifo_segment_t *fs, u32 slice_index)
 {
-  if (fss->fifos)
-    {
-      fss->fifos->prev = f;
-      f->next = fss->fifos;
-    }
-  fss->fifos = f;
+  fifo_slice_private_t *pfss = &fs->slices[slice_index];
+  svm_fifo_t *f;
+
+  f = clib_mem_bulk_alloc (pfss->fifos);
+  clib_memset (f, 0, sizeof (*f));
+  return f;
 }
 
-static inline void
-fss_fifo_del_active_list (fifo_segment_slice_t * fss, svm_fifo_t * f)
+void
+fs_fifo_free (fifo_segment_t *fs, svm_fifo_t *f)
 {
-  if (f->flags & SVM_FIFO_F_LL_TRACKED)
-    {
-      if (f->prev)
-	f->prev->next = f->next;
-      else
-	fss->fifos = f->next;
-      if (f->next)
-	f->next->prev = f->prev;
-    }
+  u32 slice_index = f->shr->slice_index;
+  fifo_slice_private_t *pfss;
+
+  pfss = &fs->slices[slice_index];
+  clib_mem_bulk_free (pfss->fifos, f);
+}
+
+void
+fifo_segment_cleanup (fifo_segment_t *fs)
+{
+  int slice_index;
+  svm_msg_q_t *mq = 0;
+
+  for (slice_index = 0; slice_index < fs->n_slices; slice_index++)
+    clib_mem_bulk_destroy (fs->slices[slice_index].fifos);
+
+  vec_foreach (fs->mqs, mq)
+    vec_free (mq->rings);
+
+  vec_free (fs->mqs);
 }
 
 /**
@@ -840,30 +783,36 @@ fifo_segment_alloc_fifo_w_slice (fifo_segment_t * fs, u32 slice_index,
 				 u32 data_bytes, fifo_segment_ftype_t ftype)
 {
   fifo_segment_header_t *fsh = fs->h;
+  fifo_slice_private_t *pfss;
   fifo_segment_slice_t *fss;
+  svm_fifo_shared_t *sf;
   svm_fifo_t *f = 0;
 
   ASSERT (slice_index < fs->n_slices);
 
-  if (PREDICT_FALSE (data_bytes > 1 << fsh->max_log2_chunk_size))
+  if (PREDICT_FALSE (data_bytes > 1 << fsh->max_log2_fifo_size))
     return 0;
 
-  fss = fsh_slice_get (fsh, slice_index);
-  f = fs_try_alloc_fifo (fsh, fss, data_bytes);
-  if (!f)
+  sf = fs_try_alloc_fifo (fsh, slice_index, data_bytes);
+  if (!sf)
     goto done;
 
-  f->slice_index = slice_index;
+  f = fs_fifo_alloc (fs, slice_index);
+  f->fs_hdr = fsh;
+  f->shr = sf;
 
   svm_fifo_init (f, data_bytes);
 
+  fss = fsh_slice_get (fsh, slice_index);
+  pfss = fs_slice_private_get (fs, slice_index);
+
   /* 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 (ftype == FIFO_SEGMENT_RX_FIFO)
     {
-      fss_fifo_add_active_list (fss, f);
+      pfss_fifo_add_active_list (pfss, f);
       f->flags |= SVM_FIFO_F_LL_TRACKED;
     }
 
@@ -874,6 +823,19 @@ done:
   return (f);
 }
 
+svm_fifo_t *
+fifo_segment_alloc_fifo_w_shared (fifo_segment_t *fs, svm_fifo_shared_t *sf)
+{
+  svm_fifo_t *f = fs_fifo_alloc (fs, 0);
+  f->fs_hdr = fs->h;
+  f->shr = sf;
+
+  f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX;
+  f->segment_index = SVM_FIFO_INVALID_INDEX;
+  f->refcnt = 1;
+  return f;
+}
+
 /**
  * Free fifo allocated in fifo segment
  */
@@ -881,44 +843,59 @@ void
 fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f)
 {
   fifo_segment_header_t *fsh = fs->h;
+  fifo_slice_private_t *pfss;
   fifo_segment_slice_t *fss;
+  svm_fifo_shared_t *sf;
 
   ASSERT (f->refcnt > 0);
 
   if (--f->refcnt > 0)
     return;
 
-  fss = fsh_slice_get (fsh, f->slice_index);
+  /*
+   * Cleanup shared state
+   */
+
+  sf = f->shr;
+  fss = fsh_slice_get (fsh, sf->slice_index);
+  pfss = fs_slice_private_get (fs, sf->slice_index);
+
+  /* Free fifo chunks */
+  fsh_slice_collect_chunks (fsh, fss, fs_chunk_ptr (fsh, f->shr->start_chunk));
+
+  sf->start_chunk = sf->end_chunk = 0;
+  sf->head_chunk = sf->tail_chunk = 0;
+
+  /* Add to free list */
+  sf->next = fss->free_fifos;
+  fss->free_fifos = sf;
+
+  fss->virtual_mem -= svm_fifo_size (f);
+
+  /*
+   *  Cleanup private state
+   */
 
   /* Remove from active list. Only rx fifos are tracked */
   if (f->flags & SVM_FIFO_F_LL_TRACKED)
     {
-      fss_fifo_del_active_list (fss, f);
+      pfss_fifo_del_active_list (pfss, f);
       f->flags &= ~SVM_FIFO_F_LL_TRACKED;
     }
 
-  /* Free fifo chunks */
-  fsh_slice_collect_chunks (fsh, fss, f->start_chunk);
-
-  f->start_chunk = f->end_chunk = 0;
-  f->head_chunk = f->tail_chunk = f->ooo_enq = f->ooo_deq = 0;
-
-  /* not allocated on segment heap */
   svm_fifo_free_chunk_lookup (f);
   svm_fifo_free_ooo_data (f);
 
   if (CLIB_DEBUG)
     {
-      f->master_session_index = ~0;
+      sf->master_session_index = ~0;
       f->master_thread_index = ~0;
     }
 
-  fss->virtual_mem -= svm_fifo_size (f);
-
-  /* Add to free list */
-  f->next = fss->free_fifos;
+  f->ooo_enq = f->ooo_deq = 0;
   f->prev = 0;
-  fss->free_fifos = f;
+
+  fs_fifo_free (fs, f);
 
   fsh_active_fifos_update (fsh, -1);
 }
@@ -926,23 +903,25 @@ fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f)
 void
 fifo_segment_detach_fifo (fifo_segment_t * fs, svm_fifo_t * f)
 {
+  fifo_slice_private_t *pfss;
   fifo_segment_slice_t *fss;
   svm_fifo_chunk_t *c;
   u32 fl_index;
 
   ASSERT (f->refcnt == 1);
 
-  fss = fsh_slice_get (fs->h, f->slice_index);
+  fss = fsh_slice_get (fs->h, f->shr->slice_index);
+  pfss = fs_slice_private_get (fs, f->shr->slice_index);
   fss->virtual_mem -= svm_fifo_size (f);
   if (f->flags & SVM_FIFO_F_LL_TRACKED)
-    fss_fifo_del_active_list (fss, f);
+    pfss_fifo_del_active_list (pfss, f);
 
-  c = f->start_chunk;
+  c = fs_chunk_ptr (fs->h, f->shr->start_chunk);
   while (c)
     {
       fl_index = fs_freelist_for_size (c->length);
       clib_atomic_fetch_sub_rel (&fss->num_chunks[fl_index], 1);
-      c = c->next;
+      c = fs_chunk_ptr (fs->h, c->next);
     }
 }
 
@@ -950,63 +929,99 @@ void
 fifo_segment_attach_fifo (fifo_segment_t * fs, svm_fifo_t * f,
 			  u32 slice_index)
 {
+  fifo_slice_private_t *pfss;
   fifo_segment_slice_t *fss;
   svm_fifo_chunk_t *c;
   u32 fl_index;
 
-  f->slice_index = slice_index;
-  fss = fsh_slice_get (fs->h, f->slice_index);
+  f->shr->slice_index = slice_index;
+  fss = fsh_slice_get (fs->h, f->shr->slice_index);
+  pfss = fs_slice_private_get (fs, f->shr->slice_index);
   fss->virtual_mem += svm_fifo_size (f);
   if (f->flags & SVM_FIFO_F_LL_TRACKED)
-    fss_fifo_add_active_list (fss, f);
+    pfss_fifo_add_active_list (pfss, f);
 
-  c = f->start_chunk;
+  c = fs_chunk_ptr (fs->h, f->shr->start_chunk);
   while (c)
     {
       fl_index = fs_freelist_for_size (c->length);
       clib_atomic_fetch_add_rel (&fss->num_chunks[fl_index], 1);
-      c = c->next;
+      c = fs_chunk_ptr (fs->h, c->next);
     }
 }
 
-int
-fifo_segment_prealloc_fifo_hdrs (fifo_segment_t * fs, u32 slice_index,
-				 u32 batch_size)
+svm_msg_q_t *
+fifo_segment_msg_q_alloc (fifo_segment_t *fs, u32 mq_index,
+			  svm_msg_q_cfg_t *cfg)
 {
   fifo_segment_header_t *fsh = fs->h;
-  fifo_segment_slice_t *fss;
-  svm_fifo_t *f;
-  void *oldheap;
-  uword size;
-  u8 *fmem;
-  int i;
+  svm_msg_q_shared_t *smq;
+  svm_msg_q_t *mq;
+  void *base;
+  u32 size;
 
-  fss = fsh_slice_get (fsh, slice_index);
-  size = (uword) (sizeof (*f)) * batch_size;
+  if (!fs->mqs)
+    {
+      u32 n_mqs = clib_max (fs->h->n_mqs, 1);
+      vec_validate (fs->mqs, n_mqs - 1);
+    }
 
-  oldheap = ssvm_push_heap (fsh->ssvm_sh);
-  fmem = clib_mem_alloc_aligned_at_offset (size, CLIB_CACHE_LINE_BYTES,
-					   0 /* align_offset */ ,
-					   0 /* os_out_of_memory */ );
-  ssvm_pop_heap (oldheap);
+  size = svm_msg_q_size_to_alloc (cfg);
+  base = fsh_alloc_aligned (fsh, size, 8);
+  fsh->n_reserved_bytes += size;
 
-  /* Out of space.. */
-  if (fmem == 0)
-    return -1;
+  smq = svm_msg_q_init (base, cfg);
+  mq = vec_elt_at_index (fs->mqs, mq_index);
+  svm_msg_q_attach (mq, smq);
 
-  /* Carve fifo + chunk space */
-  for (i = 0; i < batch_size; i++)
+  return mq;
+}
+
+svm_msg_q_t *
+fifo_segment_msg_q_attach (fifo_segment_t *fs, uword offset, u32 mq_index)
+{
+  svm_msg_q_t *mq;
+
+  if (!fs->mqs)
     {
-      f = (svm_fifo_t *) fmem;
-      memset (f, 0, sizeof (*f));
-      f->next = fss->free_fifos;
-      fss->free_fifos = f;
-      fmem += sizeof (*f);
+      u32 n_mqs = clib_max (fs->h->n_mqs, 1);
+      vec_validate (fs->mqs, n_mqs - 1);
     }
 
-  fsh_free_bytes_sub (fsh, size);
+  mq = vec_elt_at_index (fs->mqs, mq_index);
 
-  return 0;
+  if (!mq->q)
+    {
+      svm_msg_q_shared_t *smq;
+      smq = (svm_msg_q_shared_t *) ((u8 *) fs->h + offset);
+      svm_msg_q_attach (mq, smq);
+    }
+
+  ASSERT (fifo_segment_msg_q_offset (fs, mq_index) == offset);
+
+  return mq;
+}
+
+uword
+fifo_segment_msg_q_offset (fifo_segment_t *fs, u32 mq_index)
+{
+  svm_msg_q_t *mq = vec_elt_at_index (fs->mqs, mq_index);
+
+  if (mq->q == 0)
+    return ~0ULL;
+
+  return (uword) ((u8 *) mq->q - (u8 *) fs->h) - sizeof (svm_msg_q_shared_t);
+}
+
+int
+fifo_segment_prealloc_fifo_hdrs (fifo_segment_t * fs, u32 slice_index,
+				 u32 batch_size)
+{
+  fifo_segment_header_t *fsh = fs->h;
+  fifo_segment_slice_t *fss;
+
+  fss = fsh_slice_get (fsh, slice_index);
+  return fsh_try_alloc_fifo_hdr_batch (fsh, fss, batch_size);
 }
 
 int
@@ -1014,13 +1029,8 @@ fifo_segment_prealloc_fifo_chunks (fifo_segment_t * fs, u32 slice_index,
 				   u32 chunk_size, u32 batch_size)
 {
   fifo_segment_header_t *fsh = fs->h;
-  u32 rounded_data_size, fl_index;
   fifo_segment_slice_t *fss;
-  svm_fifo_chunk_t *c;
-  void *oldheap;
-  uword size;
-  u8 *cmem;
-  int i;
+  u32 fl_index;
 
   if (!fs_chunk_size_is_valid (fsh, chunk_size))
     {
@@ -1029,38 +1039,9 @@ fifo_segment_prealloc_fifo_chunks (fifo_segment_t * fs, u32 slice_index,
     }
 
   fl_index = fs_freelist_for_size (chunk_size);
-  rounded_data_size = fs_freelist_index_to_size (fl_index);
-  size = (uword) (sizeof (*c) + rounded_data_size) * batch_size;
-
-  oldheap = ssvm_push_heap (fsh->ssvm_sh);
-  cmem = clib_mem_alloc_aligned_at_offset (size, CLIB_CACHE_LINE_BYTES,
-					   0 /* align_offset */ ,
-					   0 /* os_out_of_memory */ );
-  ssvm_pop_heap (oldheap);
-
-  /* Out of space.. */
-  if (cmem == 0)
-    return -1;
-
   fss = fsh_slice_get (fsh, slice_index);
 
-  /* Carve fifo + chunk space */
-  for (i = 0; i < batch_size; i++)
-    {
-      c = (svm_fifo_chunk_t *) cmem;
-      c->start_byte = 0;
-      c->length = rounded_data_size;
-      c->next = fss->free_chunks[fl_index];
-      fss->free_chunks[fl_index] = c;
-      cmem += sizeof (*c) + rounded_data_size;
-      fsh_cached_bytes_add (fsh, rounded_data_size);
-    }
-
-  fss->num_chunks[fl_index] += batch_size;
-  fss->n_fl_chunk_bytes += batch_size * rounded_data_size;
-  fsh_free_bytes_sub (fsh, size);
-
-  return 0;
+  return fsh_try_alloc_chunk_batch (fsh, fss, fl_index, batch_size);
 }
 
 /**
@@ -1103,7 +1084,7 @@ fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
 
   /* Calculate space requirements */
   pair_size = 2 * hdrs + rx_rounded_data_size + tx_rounded_data_size;
-  space_available = fsh_free_space (fsh);
+  space_available = fsh_n_free_bytes (fsh);
   pairs_to_alloc = space_available / pair_size;
   pairs_to_alloc = clib_min (pairs_to_alloc, *n_fifo_pairs);
   pairs_per_slice = pairs_to_alloc / fs->n_slices;
@@ -1114,8 +1095,11 @@ fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
 
   for (i = 0; i < fs->n_slices; i++)
     {
-      fss = fsh_slice_get (fsh, i);
       alloc_now = clib_min (pairs_per_slice, *n_fifo_pairs);
+      if (0 == alloc_now)
+	break;
+
+      fss = fsh_slice_get (fsh, i);
       if (fs_try_alloc_fifo_batch (fsh, fss, rx_fl_index, alloc_now))
 	clib_warning ("rx prealloc failed: pairs %u", alloc_now);
       if (fs_try_alloc_fifo_batch (fsh, fss, tx_fl_index, alloc_now))
@@ -1138,7 +1122,7 @@ fifo_segment_num_fifos (fifo_segment_t * fs)
 static u32
 fs_slice_num_free_fifos (fifo_segment_slice_t * fss)
 {
-  svm_fifo_t *f;
+  svm_fifo_shared_t *f;
   u32 count = 0;
 
   f = fss->free_fifos;
@@ -1170,7 +1154,8 @@ fifo_segment_num_free_fifos (fifo_segment_t * fs)
 }
 
 static u32
-fs_slice_num_free_chunks (fifo_segment_slice_t * fss, u32 size)
+fs_slice_num_free_chunks (fifo_segment_header_t *fsh,
+			  fifo_segment_slice_t *fss, u32 size)
 {
   u32 count = 0, rounded_size, fl_index;
   svm_fifo_chunk_t *c;
@@ -1179,15 +1164,15 @@ fs_slice_num_free_chunks (fifo_segment_slice_t * fss, u32 size)
   /* Count all free chunks? */
   if (size == ~0)
     {
-      for (i = 0; i < vec_len (fss->free_chunks); i++)
+      for (i = 0; i < FS_CHUNK_VEC_LEN; i++)
 	{
-	  c = fss->free_chunks[i];
+	  c = fs_chunk_ptr (fsh, fss->free_chunks[i]);
 	  if (c == 0)
 	    continue;
 
 	  while (c)
 	    {
-	      c = c->next;
+	      c = fs_chunk_ptr (fsh, c->next);
 	      count++;
 	    }
 	}
@@ -1197,16 +1182,16 @@ fs_slice_num_free_chunks (fifo_segment_slice_t * fss, u32 size)
   rounded_size = (1 << (max_log2 (size)));
   fl_index = fs_freelist_for_size (rounded_size);
 
-  if (fl_index >= vec_len (fss->free_chunks))
+  if (fl_index >= FS_CHUNK_VEC_LEN)
     return 0;
 
-  c = fss->free_chunks[fl_index];
+  c = fs_chunk_ptr (fsh, fss->free_chunks[fl_index]);
   if (c == 0)
     return 0;
 
   while (c)
     {
-      c = c->next;
+      c = fs_chunk_ptr (fsh, c->next);
       count++;
     }
   return count;
@@ -1223,21 +1208,15 @@ fifo_segment_num_free_chunks (fifo_segment_t * fs, u32 size)
   for (slice_index = 0; slice_index < fs->n_slices; slice_index++)
     {
       fss = fsh_slice_get (fsh, slice_index);
-      count += fs_slice_num_free_chunks (fss, size);
+      count += fs_slice_num_free_chunks (fsh, fss, size);
     }
   return count;
 }
 
-void
-fifo_segment_update_free_bytes (fifo_segment_t * fs)
-{
-  fsh_update_free_bytes (fs->h);
-}
-
 uword
 fifo_segment_size (fifo_segment_t * fs)
 {
-  return fs->ssvm.ssvm_size;
+  return fs->h->max_byte_index - fs->h->n_reserved_bytes;
 }
 
 u8
@@ -1252,6 +1231,16 @@ fsh_reset_mem_limit (fifo_segment_header_t * fsh)
   fsh->flags &= ~FIFO_SEGMENT_F_MEM_LIMIT;
 }
 
+void *
+fifo_segment_alloc (fifo_segment_t *fs, uword size)
+{
+  void *rv = fsh_alloc (fs->h, size);
+  /* Mark externally allocated bytes as reserved. This helps
+   * @ref fifo_segment_size report bytes used only for fifos */
+  fs->h->n_reserved_bytes += size;
+  return rv;
+}
+
 uword
 fifo_segment_free_bytes (fifo_segment_t * fs)
 {
@@ -1281,7 +1270,7 @@ fifo_segment_fl_chunk_bytes (fifo_segment_t * fs)
   for (slice_index = 0; slice_index < fs->n_slices; slice_index++)
     {
       fss = fsh_slice_get (fsh, slice_index);
-      n_bytes += fss->n_fl_chunk_bytes;
+      n_bytes += fss_fl_chunk_bytes (fss);
     }
 
   return n_bytes;
@@ -1296,11 +1285,10 @@ fifo_segment_has_fifos (fifo_segment_t * fs)
 svm_fifo_t *
 fifo_segment_get_slice_fifo_list (fifo_segment_t * fs, u32 slice_index)
 {
-  fifo_segment_header_t *fsh = fs->h;
-  fifo_segment_slice_t *fss;
+  fifo_slice_private_t *pfss;
 
-  fss = fsh_slice_get (fsh, slice_index);
-  return fss->fifos;
+  pfss = fs_slice_private_get (fs, slice_index);
+  return pfss->active_fifos;
 }
 
 u8
@@ -1424,15 +1412,15 @@ format_fifo_segment (u8 * s, va_list * args)
   for (slice_index = 0; slice_index < fs->n_slices; slice_index++)
     {
       fss = fsh_slice_get (fsh, slice_index);
-      for (i = 0; i < vec_len (fss->free_chunks); i++)
+      for (i = 0; i < FS_CHUNK_VEC_LEN; i++)
 	{
-	  c = fss->free_chunks[i];
+	  c = fs_chunk_ptr (fsh, fss->free_chunks[i]);
 	  if (c == 0 && fss->num_chunks[i] == 0)
 	    continue;
 	  count = 0;
 	  while (c)
 	    {
-	      c = c->next;
+	      c = fs_chunk_ptr (fsh, c->next);
 	      count++;
 	    }
 
@@ -1447,7 +1435,6 @@ format_fifo_segment (u8 * s, va_list * args)
   fifo_hdr = free_fifos * sizeof (svm_fifo_t);
   est_chunk_bytes = fifo_segment_fl_chunk_bytes (fs);
   est_free_seg_bytes = fifo_segment_free_bytes (fs);
-  fifo_segment_update_free_bytes (fs);
   free_seg_bytes = fifo_segment_free_bytes (fs);
   tracked_cached_bytes = fifo_segment_cached_bytes (fs);
   allocated = fifo_segment_size (fs);