X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fsvm%2Ffifo_segment.c;h=d47c8534d144b114a44bcc850dcc71292b990974;hb=refs%2Fchanges%2F41%2F20341%2F5;hp=0263d1a57ccf04f4dcc9fdb7b2f9ed89d3c7bdca;hpb=344ce4277885e448912fdfc35bcfaf130c74d086;p=vpp.git

diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index 0263d1a57cc..d47c8534d14 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -15,6 +15,25 @@
 
 #include <svm/fifo_segment.h>
 
+/**
+ * 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 u32
+fs_free_space (fifo_segment_t * fs)
+{
+  struct dlmallinfo dlminfo;
+
+  dlminfo = mspace_mallinfo (fs->ssvm.sh->heap);
+  return dlminfo.fordblks;
+}
+
 /**
  * Initialize fifo segment shared header
  */
@@ -34,97 +53,42 @@ fifo_segment_init (fifo_segment_t * fs)
 
   ssvm_pop_heap (oldheap);
 
+  fsh->n_free_bytes = fs_free_space (fs);
   sh->ready = 1;
   return (0);
 }
 
-/**
- * Create a fifo segment in process-private memory
- */
-static int
-fifo_segment_create_process_private (fifo_segment_main_t * sm,
-				     fifo_segment_create_args_t * a)
-{
-  u32 pagesize = clib_mem_get_page_size ();
-  ssvm_shared_header_t *sh;
-  fifo_segment_t *s;
-  u32 rnd_size = 0;
-  u8 *heap;
-
-  pool_get (sm->segments, s);
-  clib_memset (s, 0, sizeof (*s));
-
-  rnd_size = (a->segment_size + (pagesize - 1)) & ~pagesize;
-
-#if USE_DLMALLOC == 0
-  heap = mheap_alloc (0, rnd_size);
-  if (heap == 0)
-    {
-      clib_unix_warning ("mheap alloc");
-      pool_put (sm->segments, s);
-      return -1;
-    }
-  {
-    mheap_t *heap_header;
-    heap_header = mheap_header (heap);
-    heap_header->flags |= MHEAP_FLAG_THREAD_SAFE;
-  }
-#else
-  heap = create_mspace (rnd_size, 1 /* locked */ );
-#endif
-
-  s->ssvm.ssvm_size = rnd_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 = ~0;
-
-  /* Allocate a [sic] shared memory header, in process memory... */
-  sh = clib_mem_alloc_aligned (sizeof (*sh), CLIB_CACHE_LINE_BYTES);
-  s->ssvm.sh = sh;
-
-  clib_memset (sh, 0, sizeof (*sh));
-  sh->heap = heap;
-
-  fifo_segment_init (s);
-  vec_add1 (a->new_segment_indices, s - sm->segments);
-
-  return (0);
-}
-
 /**
  * Create a fifo segment and initialize as master
  */
 int
 fifo_segment_create (fifo_segment_main_t * sm, fifo_segment_create_args_t * a)
 {
-  fifo_segment_t *s;
+  fifo_segment_t *fs;
+  uword baseva;
   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));
+  pool_get_zero (sm->segments, fs);
 
-  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;
+  baseva = a->segment_type == SSVM_SEGMENT_PRIVATE ? ~0ULL : sm->next_baseva;
+  fs->ssvm.ssvm_size = a->segment_size;
+  fs->ssvm.i_am_master = 1;
+  fs->ssvm.my_pid = getpid ();
+  fs->ssvm.name = format (0, "%s%c", a->segment_name, 0);
+  fs->ssvm.requested_va = baseva;
 
-  if ((rv = ssvm_master_init (&s->ssvm, a->segment_type)))
+  if ((rv = ssvm_master_init (&fs->ssvm, a->segment_type)))
     {
-      pool_put (sm->segments, s);
+      pool_put (sm->segments, fs);
       return (rv);
     }
 
   /* Note: requested_va updated due to seg base addr randomization */
-  sm->next_baseva = s->ssvm.sh->ssvm_va + a->segment_size;
+  sm->next_baseva = fs->ssvm.sh->ssvm_va + fs->ssvm.ssvm_size;
 
-  fifo_segment_init (s);
-  vec_add1 (a->new_segment_indices, s - sm->segments);
+  fifo_segment_init (fs);
+  vec_add1 (a->new_segment_indices, fs - sm->segments);
   return (0);
 }
 
@@ -190,23 +154,8 @@ fifo_segment_get_segment (fifo_segment_main_t * sm, u32 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;
-    }
+  *address = (char *) seg->ssvm.sh->ssvm_va;
+  *size = seg->ssvm.ssvm_size;
 }
 
 void
@@ -217,23 +166,16 @@ fifo_segment_main_init (fifo_segment_main_t * sm, u64 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)
+static inline u32
+fs_freelist_for_size (u32 size)
 {
-  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;
+  return max_log2 (size) - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
 }
 
-static inline int
-fs_free_list_for_size (u32 size)
+static inline u32
+fs_freelist_index_to_size (u32 fl_index)
 {
-  return max_log2 (size) - max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE);
+  return 1 << (fl_index + max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE));
 }
 
 static inline int
@@ -247,37 +189,183 @@ fs_chunk_size_is_valid (u32 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)
+static svm_fifo_t *
+fs_try_alloc_fifo_freelist (fifo_segment_t * fs, u32 fl_index, u32 data_bytes)
 {
-  u32 size, rounded_data_size;
-  int i, fl_index;
-  u8 *fifos_mem;
+  fifo_segment_header_t *fsh = fs->h;
+  svm_fifo_chunk_t *c;
   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);
+  f = fsh->free_fifos;
+  c = fsh->free_chunks[fl_index];
+
+  if (!f || !c)
+    return 0;
 
-  /* Calculate space requirement $$$ round-up data_size_in_bytes */
-  size = (sizeof (*f) + rounded_data_size) * chunk_size;
+  fsh->free_fifos = f->next;
+  fsh->free_chunks[fl_index] = c->next;
+  c->next = c;
+  c->start_byte = 0;
+  c->length = data_bytes;
+  memset (f, 0, sizeof (*f));
+  f->start_chunk = c;
+  f->end_chunk = c;
+
+  fsh->n_fl_chunk_bytes -= fs_freelist_index_to_size (fl_index);
+  return f;
+}
 
-  /* 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 */ );
+static svm_fifo_t *
+fs_try_alloc_fifo_freelist_multi_chunk (fifo_segment_t * fs, u32 data_bytes)
+{
+  svm_fifo_chunk_t *c, *first = 0, *last = 0;
+  fifo_segment_header_t *fsh = fs->h;
+  u32 fl_index, fl_size, n_alloc = 0;
+  svm_fifo_t *f;
+
+  f = fsh->free_fifos;
+  if (!f)
+    {
+      void *oldheap = ssvm_push_heap (fs->ssvm.sh);
+      f = clib_mem_alloc_aligned (sizeof (*f), CLIB_CACHE_LINE_BYTES);
+      ssvm_pop_heap (oldheap);
+      if (!f)
+	return 0;
+      memset (f, 0, sizeof (*f));
+    }
+
+  fl_index = fs_freelist_for_size (data_bytes) - 1;
+  vec_validate_init_empty (fsh->free_chunks, fl_index, 0);
+  fl_size = fs_freelist_index_to_size (fl_index);
+
+  while (data_bytes)
+    {
+      c = fsh->free_chunks[fl_index];
+      if (c)
+	{
+	  fsh->free_chunks[fl_index] = c->next;
+	  if (!last)
+	    last = c;
+	  c->next = first;
+	  first = c;
+	  n_alloc += fl_size;
+	  c->length = clib_min (fl_size, data_bytes);
+	  data_bytes -= c->length;
+	}
+      else
+	{
+	  ASSERT (fl_index > 0);
+	  fl_index -= 1;
+	  fl_size = fl_size >> 1;
+	}
+    }
+  f->start_chunk = first;
+  f->end_chunk = last;
+  last->next = first;
+  fsh->n_fl_chunk_bytes -= n_alloc;
+  return f;
+}
+
+static int
+fs_try_alloc_fifo_batch (fifo_segment_t * fs, u32 fl_index, u32 batch_size)
+{
+  fifo_segment_header_t *fsh = fs->h;
+  u32 size, hdrs, rounded_data_size;
+  svm_fifo_chunk_t *c;
+  svm_fifo_t *f;
+  void *oldheap;
+  u8 *fmem;
+  int i;
+
+  vec_validate_init_empty (fsh->free_chunks, fl_index, 0);
+  rounded_data_size = fs_freelist_index_to_size (fl_index);
+  hdrs = sizeof (*f) + sizeof (*c);
+  size = (hdrs + rounded_data_size) * batch_size;
+
+  oldheap = ssvm_push_heap (fs->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 (fifos_mem == 0)
-    return;
+  if (fmem == 0)
+    return -1;
 
-  /* Carve fifo space */
-  for (i = 0; i < chunk_size; i++)
+  /* Carve fifo + chunk space */
+  for (i = 0; i < batch_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;
+      f = (svm_fifo_t *) fmem;
+      memset (f, 0, sizeof (*f));
+      f->next = fsh->free_fifos;
+      fsh->free_fifos = f;
+      c = (svm_fifo_chunk_t *) (fmem + sizeof (*f));
+      c->start_byte = 0;
+      c->length = rounded_data_size;
+      c->next = fsh->free_chunks[fl_index];
+      fsh->free_chunks[fl_index] = c;
+      fmem += hdrs + rounded_data_size;
     }
+
+  fsh->n_fl_chunk_bytes += batch_size * rounded_data_size;
+  fsh->n_free_bytes -= size;
+
+  return 0;
+}
+
+/**
+ * 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_t * fs, u32 data_bytes)
+{
+  fifo_segment_header_t *fsh = fs->h;
+  u32 fifo_sz, fl_index;
+  svm_fifo_t *f = 0;
+
+  fl_index = fs_freelist_for_size (data_bytes);
+  vec_validate_init_empty (fsh->free_chunks, fl_index, 0);
+  fifo_sz = sizeof (svm_fifo_t) + sizeof (svm_fifo_chunk_t);
+  fifo_sz += 1 << max_log2 (data_bytes);
+
+  if (fsh->free_fifos && fsh->free_chunks[fl_index])
+    {
+      f = fs_try_alloc_fifo_freelist (fs, fl_index, data_bytes);
+      if (f)
+	goto done;
+    }
+  if (fifo_sz * FIFO_SEGMENT_ALLOC_BATCH_SIZE < fsh->n_free_bytes)
+    {
+      if (fs_try_alloc_fifo_batch (fs, fl_index,
+				   FIFO_SEGMENT_ALLOC_BATCH_SIZE))
+	goto done;
+
+      f = fs_try_alloc_fifo_freelist (fs, fl_index, data_bytes);
+      goto done;
+    }
+  if (fifo_sz <= fsh->n_free_bytes)
+    {
+      void *oldheap = ssvm_push_heap (fs->ssvm.sh);
+      f = svm_fifo_create (data_bytes);
+      ssvm_pop_heap (oldheap);
+      if (f)
+	{
+	  fsh->n_free_bytes -= fifo_sz;
+	  goto done;
+	}
+    }
+  if (data_bytes <= fsh->n_fl_chunk_bytes)
+    f = fs_try_alloc_fifo_freelist_multi_chunk (fs, data_bytes);
+
+done:
+
+  return f;
 }
 
 /**
@@ -288,10 +376,7 @@ 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_t *f = 0;
-  void *oldheap;
-  int fl_index;
 
   if (!fs_chunk_size_is_valid (data_bytes))
     {
@@ -299,45 +384,16 @@ fifo_segment_alloc_fifo (fifo_segment_t * fs, u32 data_bytes,
       return 0;
     }
 
-  fl_index = fs_free_list_for_size (data_bytes);
-
-  sh = fs->ssvm.sh;
-  ssvm_lock_non_recursive (sh, 1);
-
   fsh = fs->h;
-  vec_validate_init_empty (fsh->free_fifos, fl_index, 0);
-  f = fsh->free_fifos[fl_index];
-
-  /* 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;
-    }
-
-  /* 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_bytes);
-  ssvm_pop_heap (oldheap);
+  ssvm_lock_non_recursive (fs->ssvm.sh, 1);
 
-  if (PREDICT_FALSE (f == 0))
+  f = fs_try_alloc_fifo (fs, data_bytes);
+  if (!f)
     goto done;
 
-  f->freelist_index = fl_index;
+  /* (re)initialize the fifo, as in svm_fifo_create */
+  svm_fifo_init (f, data_bytes);
 
-found:
   /* 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
@@ -355,7 +411,7 @@ found:
   fsh->n_active_fifos++;
 
 done:
-  ssvm_unlock_non_recursive (sh);
+  ssvm_unlock_non_recursive (fs->ssvm.sh);
   return (f);
 }
 
@@ -365,8 +421,10 @@ done:
 void
 fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f)
 {
+  svm_fifo_chunk_t *cur, *next;
   fifo_segment_header_t *fsh;
   ssvm_shared_header_t *sh;
+  void *oldheap;
   int fl_index;
 
   ASSERT (f->refcnt > 0);
@@ -376,9 +434,6 @@ fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f)
 
   sh = fs->ssvm.sh;
   fsh = fs->h;
-  fl_index = f->freelist_index;
-
-  ASSERT (fl_index < vec_len (fsh->free_fifos));
 
   ssvm_lock_non_recursive (sh, 2);
 
@@ -395,29 +450,30 @@ fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f)
     }
 
   /* Add to free list */
-  f->next = fsh->free_fifos[fl_index];
+  f->next = fsh->free_fifos;
   f->prev = 0;
-  fsh->free_fifos[fl_index] = f;
+  fsh->free_fifos = f;
 
-  /* If fifo has more chunks, free them */
-  if (f->flags & SVM_FIFO_F_MULTI_CHUNK)
+  /* Free fifo chunks */
+  cur = f->start_chunk;
+  do
     {
-      svm_fifo_chunk_t *cur, *next;
-      void *oldheap;
-
-      next = f->start_chunk->next;
-      while (next != f->start_chunk)
-	{
-	  cur = next;
-	  next = next->next;
-	  fl_index = fs_free_list_for_size (cur->length);
-	  cur->next = fsh->free_chunks[fl_index];
-	  fsh->free_chunks[fl_index] = cur;
-	}
-      oldheap = ssvm_push_heap (sh);
-      svm_fifo_free_chunk_lookup (f);
-      ssvm_pop_heap (oldheap);
+      next = cur->next;
+      fl_index = fs_freelist_for_size (cur->length);
+      ASSERT (fl_index < vec_len (fsh->free_chunks));
+      cur->next = fsh->free_chunks[fl_index];
+      fsh->free_chunks[fl_index] = cur;
+      fsh->n_fl_chunk_bytes += fs_freelist_index_to_size (fl_index);
+      cur = next;
     }
+  while (cur != f->start_chunk);
+
+  f->start_chunk = f->end_chunk = f->new_chunks = 0;
+  f->head_chunk = f->tail_chunk = f->ooo_enq = f->ooo_deq = 0;
+
+  oldheap = ssvm_push_heap (sh);
+  svm_fifo_free_chunk_lookup (f);
+  ssvm_pop_heap (oldheap);
 
   /* not allocated on segment heap */
   svm_fifo_free_ooo_data (f);
@@ -432,6 +488,92 @@ fifo_segment_free_fifo (fifo_segment_t * fs, svm_fifo_t * f)
   ssvm_unlock_non_recursive (sh);
 }
 
+int
+fifo_segment_prealloc_fifo_hdrs (fifo_segment_t * fs, u32 batch_size)
+{
+  fifo_segment_header_t *fsh = fs->h;
+  svm_fifo_t *f;
+  void *oldheap;
+  u32 size;
+  u8 *fmem;
+  int i;
+
+  size = (sizeof (*f)) * batch_size;
+
+  oldheap = ssvm_push_heap (fs->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 + chunk space */
+  for (i = 0; i < batch_size; i++)
+    {
+      f = (svm_fifo_t *) fmem;
+      memset (f, 0, sizeof (*f));
+      f->next = fsh->free_fifos;
+      fsh->free_fifos = f;
+      fmem += sizeof (*f);
+    }
+
+  fsh->n_free_bytes -= size;
+
+  return 0;
+}
+
+int
+fifo_segment_prealloc_fifo_chunks (fifo_segment_t * fs, u32 chunk_size,
+				   u32 batch_size)
+{
+  fifo_segment_header_t *fsh = fs->h;
+  u32 size, rounded_data_size, fl_index;
+  svm_fifo_chunk_t *c;
+  void *oldheap;
+  u8 *cmem;
+  int i;
+
+  if (!fs_chunk_size_is_valid (chunk_size))
+    {
+      clib_warning ("chunk size out of range %d", chunk_size);
+      return -1;
+    }
+
+  fl_index = fs_freelist_for_size (chunk_size);
+  vec_validate_init_empty (fsh->free_chunks, fl_index, 0);
+  rounded_data_size = fs_freelist_index_to_size (fl_index);
+  size = (sizeof (*c) + rounded_data_size) * batch_size;
+
+  oldheap = ssvm_push_heap (fs->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;
+
+  /* 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 = fsh->free_chunks[fl_index];
+      fsh->free_chunks[fl_index] = c;
+      cmem += sizeof (*c) + rounded_data_size;
+    }
+
+  fsh->n_fl_chunk_bytes += batch_size * rounded_data_size;
+  fsh->n_free_bytes -= size;
+
+  return 0;
+}
+
 /**
  * Pre-allocates fifo pairs in fifo segment
  */
@@ -440,15 +582,10 @@ fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
 				     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;
-  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;
+  u32 rx_rounded_data_size, tx_rounded_data_size, pair_size, pairs_to_alloc;
+  int rx_fl_index, tx_fl_index;
   uword space_available;
-  void *oldheap;
-  svm_fifo_t *f;
+  u32 hdrs;
 
   /* Parameter check */
   if (rx_fifo_size == 0 || tx_fifo_size == 0 || *n_fifo_pairs == 0)
@@ -467,62 +604,24 @@ fifo_segment_preallocate_fifo_pairs (fifo_segment_t * fs,
     }
 
   rx_rounded_data_size = (1 << (max_log2 (rx_fifo_size)));
-  rx_fl_index = fs_free_list_for_size (rx_fifo_size);
+  rx_fl_index = fs_freelist_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);
+  tx_fl_index = fs_freelist_for_size (tx_fifo_size);
 
-  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;
-    }
+  hdrs = sizeof (svm_fifo_t) + sizeof (svm_fifo_chunk_t);
 
-  /* 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;
+  /* Calculate space requirements */
+  pair_size = 2 * hdrs + rx_rounded_data_size + tx_rounded_data_size;
+  space_available = fs_free_space (fs);
+  pairs_to_alloc = clib_min (space_available / pair_size, *n_fifo_pairs);
 
-      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;
-    }
+  if (fs_try_alloc_fifo_batch (fs, rx_fl_index, pairs_to_alloc))
+    clib_warning ("rx prealloc failed");
+  if (fs_try_alloc_fifo_batch (fs, tx_fl_index, pairs_to_alloc))
+    clib_warning ("tx prealloc failed");
 
   /* Account for the pairs allocated */
-  *n_fifo_pairs -= pairs_to_allocate;
-  ssvm_pop_heap (oldheap);
+  *n_fifo_pairs -= pairs_to_alloc;
 }
 
 int
@@ -536,10 +635,10 @@ fifo_segment_grow_fifo (fifo_segment_t * fs, svm_fifo_t * f, u32 chunk_size)
   if (!fs_chunk_size_is_valid (chunk_size))
     {
       clib_warning ("chunk size out of range %d", chunk_size);
-      return 0;
+      return -1;
     }
 
-  fl_index = fs_free_list_for_size (chunk_size);
+  fl_index = fs_freelist_for_size (chunk_size);
 
   sh = fs->ssvm.sh;
   ssvm_lock_non_recursive (sh, 1);
@@ -555,12 +654,15 @@ fifo_segment_grow_fifo (fifo_segment_t * fs, svm_fifo_t * f, u32 chunk_size)
       if (!c)
 	{
 	  ssvm_pop_heap (oldheap);
+	  ssvm_unlock_non_recursive (sh);
 	  return -1;
 	}
     }
   else
     {
       fs->h->free_chunks[fl_index] = c->next;
+      c->next = 0;
+      fs->h->n_fl_chunk_bytes -= fs_freelist_index_to_size (fl_index);
     }
 
   svm_fifo_add_chunk (f, c);
@@ -587,7 +689,7 @@ fifo_segment_collect_fifo_chunks (fifo_segment_t * fs, svm_fifo_t * f)
   while (cur)
     {
       next = cur->next;
-      fl_index = fs_free_list_for_size (cur->length);
+      fl_index = fs_freelist_for_size (cur->length);
       cur->next = fs->h->free_chunks[fl_index];
       fs->h->free_chunks[fl_index] = cur;
       cur = next;
@@ -609,42 +711,13 @@ fifo_segment_num_fifos (fifo_segment_t * fs)
 }
 
 u32
-fifo_segment_num_free_fifos (fifo_segment_t * fs, u32 fifo_size_in_bytes)
+fifo_segment_num_free_fifos (fifo_segment_t * fs)
 {
-  u32 count = 0, rounded_data_size, fl_index;
-  fifo_segment_header_t *fsh;
-  ssvm_shared_header_t *sh;
+  fifo_segment_header_t *fsh = fs->h;
   svm_fifo_t *f;
-  int i;
+  u32 count = 0;
 
-  sh = fs->ssvm.sh;
-  fsh = (fifo_segment_header_t *) sh->opaque[0];
-
-  /* Count all free fifos? */
-  if (fifo_size_in_bytes == ~0)
-    {
-      for (i = 0; i < vec_len (fsh->free_fifos); i++)
-	{
-	  f = fsh->free_fifos[i];
-	  if (f == 0)
-	    continue;
-
-	  while (f)
-	    {
-	      f = f->next;
-	      count++;
-	    }
-	}
-      return count;
-    }
-
-  rounded_data_size = (1 << (max_log2 (fifo_size_in_bytes)));
-  fl_index = fs_free_list_for_size (rounded_data_size);
-
-  if (fl_index >= vec_len (fsh->free_fifos))
-    return 0;
-
-  f = fsh->free_fifos[fl_index];
+  f = fsh->free_fifos;
   if (f == 0)
     return 0;
 
@@ -685,7 +758,7 @@ fifo_segment_num_free_chunks (fifo_segment_t * fs, u32 size)
     }
 
   rounded_size = (1 << (max_log2 (size)));
-  fl_index = fs_free_list_for_size (rounded_size);
+  fl_index = fs_freelist_for_size (rounded_size);
 
   if (fl_index >= vec_len (fsh->free_chunks))
     return 0;
@@ -702,6 +775,24 @@ fifo_segment_num_free_chunks (fifo_segment_t * fs, u32 size)
   return count;
 }
 
+void
+fifo_segment_update_free_bytes (fifo_segment_t * fs)
+{
+  fs->h->n_free_bytes = fs_free_space (fs);
+}
+
+u32
+fifo_segment_free_bytes (fifo_segment_t * fs)
+{
+  return fs->h->n_free_bytes;
+}
+
+u32
+fifo_segment_fl_chunk_bytes (fifo_segment_t * fs)
+{
+  return fs->h->n_fl_chunk_bytes;
+}
+
 u8
 fifo_segment_has_fifos (fifo_segment_t * fs)
 {
@@ -738,38 +829,64 @@ format_fifo_segment_type (u8 * s, va_list * args)
 u8 *
 format_fifo_segment (u8 * s, va_list * args)
 {
-  fifo_segment_t *sp = va_arg (*args, fifo_segment_t *);
+  fifo_segment_t *fs = va_arg (*args, fifo_segment_t *);
   int verbose __attribute__ ((unused)) = va_arg (*args, int);
-  fifo_segment_header_t *fsh = sp->h;
+  fifo_segment_header_t *fsh;
+  svm_fifo_chunk_t *c;
   u32 count, indent;
-  svm_fifo_t *f;
+  u32 active_fifos;
+  u32 free_fifos;
+  char *address;
+  size_t size;
   int i;
 
   indent = format_get_indent (s) + 2;
 #if USE_DLMALLOC == 0
   s = format (s, "%U segment heap: %U\n", format_white_space, indent,
-	      format_mheap, svm_fifo_segment_heap (sp), verbose);
+	      format_mheap, svm_fifo_segment_heap (fs), verbose);
   s = format (s, "%U segment has %u active fifos\n",
-	      format_white_space, indent, fifo_segment_num_fifos (sp));
+	      format_white_space, indent, fifo_segment_num_fifos (fs));
 #endif
 
-  for (i = 0; i < vec_len (fsh->free_fifos); i++)
+  if (fs == 0)
     {
-      f = fsh->free_fifos[i];
-      if (f == 0)
+      s = format (s, "%-15s%15s%15s%15s%15s%15s", "Name", "Type",
+		  "HeapSize (M)", "ActiveFifos", "FreeFifos", "Address");
+      return s;
+    }
+
+  fsh = fs->h;
+  fifo_segment_info (fs, &address, &size);
+  active_fifos = fifo_segment_num_fifos (fs);
+  free_fifos = fifo_segment_num_free_fifos (fs);
+
+  s = format (s, "%-15v%15U%15llu%15u%15u%15llx", ssvm_name (&fs->ssvm),
+	      format_fifo_segment_type, fs, size >> 20ULL, active_fifos,
+	      free_fifos, address);
+
+  if (!verbose)
+    return s;
+
+  s = format (s, "\n");
+  for (i = 0; i < vec_len (fsh->free_chunks); i++)
+    {
+      c = fsh->free_chunks[i];
+      if (c == 0)
 	continue;
       count = 0;
-      while (f)
+      while (c)
 	{
-	  f = f->next;
+	  c = c->next;
 	  count++;
 	}
 
-      s = format (s, "%U%-5u Kb: %u free",
-		  format_white_space, indent + 2,
+      s = format (s, "%U%-5u Kb: %u free", format_white_space, indent + 2,
 		  1 << (i + max_log2 (FIFO_SEGMENT_MIN_FIFO_SIZE) - 10),
 		  count);
     }
+  s = format (s, "%Ufree bytes %U", format_white_space, indent + 2,
+	      format_memory_size, fsh->n_free_bytes);
+
   return s;
 }