Overall tcp performance improvements (VPP-846)
[vpp.git] / src / svm / svm_fifo.c
index 07b0d2d..6ca437c 100644 (file)
 
 #include <svm/svm_fifo.h>
 
+static inline u8
+position_lt (svm_fifo_t * f, u32 a, u32 b)
+{
+  return (ooo_segment_distance_to_tail (f, a)
+         < ooo_segment_distance_to_tail (f, b));
+}
+
+static inline u8
+position_leq (svm_fifo_t * f, u32 a, u32 b)
+{
+  return (ooo_segment_distance_to_tail (f, a)
+         <= ooo_segment_distance_to_tail (f, b));
+}
+
+static inline u8
+position_gt (svm_fifo_t * f, u32 a, u32 b)
+{
+  return (ooo_segment_distance_to_tail (f, a)
+         > ooo_segment_distance_to_tail (f, b));
+}
+
+static inline u32
+position_diff (svm_fifo_t * f, u32 posa, u32 posb)
+{
+  return ooo_segment_distance_to_tail (f, posa)
+    - ooo_segment_distance_to_tail (f, posb);
+}
+
+static inline u32
+ooo_segment_end_pos (svm_fifo_t * f, ooo_segment_t * s)
+{
+  return (s->start + s->length) % f->nitems;
+}
+
+u8 *
+format_ooo_segment (u8 * s, va_list * args)
+{
+  ooo_segment_t *seg = va_arg (*args, ooo_segment_t *);
+
+  s = format (s, "pos %u, len %u, next %d, prev %d",
+             seg->start, seg->length, seg->next, seg->prev);
+  return s;
+}
+
+u8 *
+format_ooo_list (u8 * s, va_list * args)
+{
+  svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+  u32 ooo_segment_index = f->ooos_list_head;
+  ooo_segment_t *seg;
+
+  while (ooo_segment_index != OOO_SEGMENT_INVALID_INDEX)
+    {
+      seg = pool_elt_at_index (f->ooo_segments, ooo_segment_index);
+      s = format (s, "  %U\n", format_ooo_segment, seg);
+      ooo_segment_index = seg->next;
+    }
+  return s;
+}
+
+u8 *
+format_svm_fifo (u8 * s, va_list * args)
+{
+  svm_fifo_t *f = va_arg (*args, svm_fifo_t *);
+  int verbose = va_arg (*args, int);
+
+  s = format (s, "cursize %u nitems %u has_event %d\n",
+             f->cursize, f->nitems, f->has_event);
+  s = format (s, " head %d tail %d\n", f->head, f->tail);
+
+  if (verbose > 1)
+    s = format
+      (s, " server session %d thread %d client session %d thread %d\n",
+       f->master_session_index, f->master_thread_index,
+       f->client_session_index, f->client_thread_index);
+
+  if (verbose)
+    {
+      s = format (s, " ooo pool %d active elts\n",
+                 pool_elts (f->ooo_segments));
+      if (svm_fifo_has_ooo_data (f))
+       s = format (s, " %U", format_ooo_list, f);
+    }
+  return s;
+}
+
 /** create an svm fifo, in the current heap. Fails vs blow up the process */
 svm_fifo_t *
 svm_fifo_create (u32 data_size_in_bytes)
 {
   svm_fifo_t *f;
-  pthread_mutexattr_t attr;
-  pthread_condattr_t cattr;
 
   f = clib_mem_alloc_aligned_or_null (sizeof (*f) + data_size_in_bytes,
                                      CLIB_CACHE_LINE_BYTES);
@@ -32,29 +116,16 @@ svm_fifo_create (u32 data_size_in_bytes)
   f->nitems = data_size_in_bytes;
   f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX;
 
-  memset (&attr, 0, sizeof (attr));
-  memset (&cattr, 0, sizeof (cattr));
-
-  if (pthread_mutexattr_init (&attr))
-    clib_unix_warning ("mutexattr_init");
-  if (pthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED))
-    clib_unix_warning ("pthread_mutexattr_setpshared");
-  if (pthread_mutex_init (&f->mutex, &attr))
-    clib_unix_warning ("mutex_init");
-  if (pthread_mutexattr_destroy (&attr))
-    clib_unix_warning ("mutexattr_destroy");
-  if (pthread_condattr_init (&cattr))
-    clib_unix_warning ("condattr_init");
-  if (pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED))
-    clib_unix_warning ("condattr_setpshared");
-  if (pthread_cond_init (&f->condvar, &cattr))
-    clib_unix_warning ("cond_init1");
-  if (pthread_condattr_destroy (&cattr))
-    clib_unix_warning ("cond_init2");
-
   return (f);
 }
 
+void
+svm_fifo_free (svm_fifo_t * f)
+{
+  pool_free (f->ooo_segments);
+  clib_mem_free (f);
+}
+
 always_inline ooo_segment_t *
 ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
 {
@@ -62,7 +133,7 @@ ooo_segment_new (svm_fifo_t * f, u32 start, u32 length)
 
   pool_get (f->ooo_segments, s);
 
-  s->fifo_position = start;
+  s->start = start;
   s->length = length;
 
   s->prev = s->next = OOO_SEGMENT_INVALID_INDEX;
@@ -103,14 +174,17 @@ static void
 ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
 {
   ooo_segment_t *s, *new_s, *prev, *next, *it;
-  u32 new_index, position, end_offset, s_sof, s_eof, s_index;
+  u32 new_index, s_end_pos, s_index;
+  u32 normalized_position, normalized_end_position;
+
+  normalized_position = (f->tail + offset) % f->nitems;
+  normalized_end_position = (f->tail + offset + length) % f->nitems;
 
-  position = (f->tail + offset) % f->nitems;
-  end_offset = offset + length;
+  f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
 
   if (f->ooos_list_head == OOO_SEGMENT_INVALID_INDEX)
     {
-      s = ooo_segment_new (f, position, length);
+      s = ooo_segment_new (f, normalized_position, length);
       f->ooos_list_head = s - f->ooo_segments;
       f->ooos_newest = f->ooos_list_head;
       return;
@@ -119,26 +193,33 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
   /* Find first segment that starts after new segment */
   s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
   while (s->next != OOO_SEGMENT_INVALID_INDEX
-        && ooo_segment_offset (f, s) <= offset)
+        && position_lt (f, s->start, normalized_position))
     s = pool_elt_at_index (f->ooo_segments, s->next);
 
+  /* If we have a previous and we overlap it, use it as starting point */
+  prev = ooo_segment_get_prev (f, s);
+  if (prev
+      && position_leq (f, normalized_position, ooo_segment_end_pos (f, prev)))
+    {
+      s = prev;
+      s_end_pos = ooo_segment_end_pos (f, s);
+      goto merge;
+    }
+
   s_index = s - f->ooo_segments;
-  s_sof = ooo_segment_offset (f, s);
-  s_eof = ooo_segment_end_offset (f, s);
+  s_end_pos = ooo_segment_end_pos (f, s);
 
   /* No overlap, add before current segment */
-  if (end_offset < s_sof)
+  if (position_lt (f, normalized_end_position, s->start))
     {
-      new_s = ooo_segment_new (f, position, length);
+      new_s = ooo_segment_new (f, normalized_position, length);
       new_index = new_s - f->ooo_segments;
 
       /* Pool might've moved, get segment again */
       s = pool_elt_at_index (f->ooo_segments, s_index);
-
       if (s->prev != OOO_SEGMENT_INVALID_INDEX)
        {
          new_s->prev = s->prev;
-
          prev = pool_elt_at_index (f->ooo_segments, new_s->prev);
          prev->next = new_index;
        }
@@ -148,29 +229,23 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
          f->ooos_list_head = new_index;
        }
 
-      new_s->next = s - f->ooo_segments;
+      new_s->next = s_index;
       s->prev = new_index;
       f->ooos_newest = new_index;
       return;
     }
   /* No overlap, add after current segment */
-  else if (s_eof < offset)
+  else if (position_gt (f, normalized_position, s_end_pos))
     {
-      new_s = ooo_segment_new (f, position, length);
+      new_s = ooo_segment_new (f, normalized_position, length);
       new_index = new_s - f->ooo_segments;
 
       /* Pool might've moved, get segment again */
       s = pool_elt_at_index (f->ooo_segments, s_index);
 
-      if (s->next != OOO_SEGMENT_INVALID_INDEX)
-       {
-         new_s->next = s->next;
-
-         next = pool_elt_at_index (f->ooo_segments, new_s->next);
-         next->prev = new_index;
-       }
+      ASSERT (s->next == OOO_SEGMENT_INVALID_INDEX);
 
-      new_s->prev = s - f->ooo_segments;
+      new_s->prev = s_index;
       s->next = new_index;
       f->ooos_newest = new_index;
 
@@ -181,68 +256,54 @@ ooo_segment_add (svm_fifo_t * f, u32 offset, u32 length)
    * Merge needed
    */
 
+merge:
+
   /* Merge at head */
-  if (offset <= s_sof)
+  if (position_lt (f, normalized_position, s->start))
     {
-      /* If we have a previous, check if we overlap */
-      if (s->prev != OOO_SEGMENT_INVALID_INDEX)
-       {
-         prev = pool_elt_at_index (f->ooo_segments, s->prev);
-
-         /* New segment merges prev and current. Remove previous and
-          * update position of current. */
-         if (ooo_segment_end_offset (f, prev) >= offset)
-           {
-             s->fifo_position = prev->fifo_position;
-             s->length = s_eof - ooo_segment_offset (f, prev);
-             ooo_segment_del (f, s->prev);
-           }
-       }
-      else
-       {
-         s->fifo_position = position;
-         s->length = s_eof - ooo_segment_offset (f, s);
-       }
-
-      /* The new segment's tail may cover multiple smaller ones */
-      if (s_eof < end_offset)
-       {
-         /* Remove segments completely covered */
-         it = (s->next != OOO_SEGMENT_INVALID_INDEX) ?
-           pool_elt_at_index (f->ooo_segments, s->next) : 0;
-         while (it && ooo_segment_end_offset (f, it) < end_offset)
-           {
-             next = (it->next != OOO_SEGMENT_INVALID_INDEX) ?
-               pool_elt_at_index (f->ooo_segments, it->next) : 0;
-             ooo_segment_del (f, it - f->ooo_segments);
-             it = next;
-           }
-
-         /* Update length. Segment's start might have changed. */
-         s->length = end_offset - ooo_segment_offset (f, s);
-
-         /* If partial overlap with last, merge */
-         if (it && ooo_segment_offset (f, it) < end_offset)
-           {
-             s->length +=
-               it->length - (ooo_segment_offset (f, it) - end_offset);
-             ooo_segment_del (f, it - f->ooo_segments);
-           }
-       }
+      s->start = normalized_position;
+      s->length = position_diff (f, s_end_pos, s->start);
     }
-  /* Last but overlapping previous */
-  else if (s_eof <= end_offset)
+  /* Overlapping tail */
+  else if (position_gt (f, normalized_end_position, s_end_pos))
     {
-      s->length = end_offset - ooo_segment_offset (f, s);
+      s->length = position_diff (f, normalized_end_position, s->start);
     }
   /* New segment completely covered by current one */
   else
     {
       /* Do Nothing */
+      s = 0;
+      goto done;
+    }
+
+  /* The new segment's tail may cover multiple smaller ones */
+  if (position_gt (f, normalized_end_position, s_end_pos))
+    {
+      /* Remove the completely overlapped segments */
+      it = (s->next != OOO_SEGMENT_INVALID_INDEX) ?
+       pool_elt_at_index (f->ooo_segments, s->next) : 0;
+      while (it && position_leq (f, ooo_segment_end_pos (f, it),
+                                normalized_end_position))
+       {
+         next = (it->next != OOO_SEGMENT_INVALID_INDEX) ?
+           pool_elt_at_index (f->ooo_segments, it->next) : 0;
+         ooo_segment_del (f, it - f->ooo_segments);
+         it = next;
+       }
+
+      /* If partial overlap with last, merge */
+      if (it && position_leq (f, it->start, normalized_end_position))
+       {
+         s->length = ooo_segment_end_pos (f, it) - s->start;
+         ooo_segment_del (f, it - f->ooo_segments);
+       }
     }
 
+done:
   /* Most recently updated segment */
-  f->ooos_newest = s - f->ooo_segments;
+  if (s)
+    f->ooos_newest = s - f->ooo_segments;
 }
 
 /**
@@ -253,63 +314,64 @@ static int
 ooo_segment_try_collect (svm_fifo_t * f, u32 n_bytes_enqueued)
 {
   ooo_segment_t *s;
-  u32 index, bytes = 0, diff;
+  u32 index, bytes = 0;
+  i32 diff;
 
   s = pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
 
+  diff = (f->tail >= s->start) ?
+    f->tail - s->start : f->nitems + f->tail - s->start;
+
+  if (diff > n_bytes_enqueued)
+    return 0;
+
   /* If last tail update overlaps one/multiple ooo segments, remove them */
-  diff = (f->nitems + f->tail - s->fifo_position) % f->nitems;
-  while (0 < diff && diff < n_bytes_enqueued)
+  while (0 <= diff && diff < n_bytes_enqueued)
     {
-      /* Segment end is beyond the tail. Advance tail and be done */
-      if (diff < s->length)
+      index = s - f->ooo_segments;
+
+      /* Segment end is beyond the tail. Advance tail and remove segment */
+      if (s->length > diff)
        {
-         f->tail += s->length - diff;
+         bytes = s->length - diff;
+         f->tail += bytes;
          f->tail %= f->nitems;
+         ooo_segment_del (f, index);
          break;
        }
+
       /* If we have next go on */
-      else if (s->next != OOO_SEGMENT_INVALID_INDEX)
+      if (s->next != OOO_SEGMENT_INVALID_INDEX)
        {
-         index = s - f->ooo_segments;
          s = pool_elt_at_index (f->ooo_segments, s->next);
-         diff = (f->nitems + f->tail - s->fifo_position) % f->nitems;
+         diff = (f->tail >= s->start) ?
+           f->tail - s->start : f->nitems + f->tail - s->start;
          ooo_segment_del (f, index);
        }
       /* End of search */
       else
        {
+         ooo_segment_del (f, index);
          break;
        }
     }
 
-  /* If tail is adjacent to an ooo segment, 'consume' it */
-  if (diff == 0)
-    {
-      bytes = ((f->nitems - f->cursize) >= s->length) ? s->length :
-       f->nitems - f->cursize;
-
-      f->tail += bytes;
-      f->tail %= f->nitems;
-
-      ooo_segment_del (f, s - f->ooo_segments);
-    }
-
   return bytes;
 }
 
 static int
-svm_fifo_enqueue_internal (svm_fifo_t * f,
-                          int pid, u32 max_bytes, u8 * copy_from_here)
+svm_fifo_enqueue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems;
 
-  if (PREDICT_FALSE (f->cursize == f->nitems))
+  /* read cursize, which can only increase while we're working */
+  cursize = svm_fifo_max_dequeue (f);
+  f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
+
+  if (PREDICT_FALSE (cursize == f->nitems))
     return -2;                 /* fifo stuffed */
 
-  /* read cursize, which can only decrease while we're working */
-  cursize = f->cursize;
   nitems = f->nitems;
 
   /* Number of bytes we're going to copy */
@@ -356,10 +418,9 @@ svm_fifo_enqueue_internal (svm_fifo_t * f,
 }
 
 int
-svm_fifo_enqueue_nowait (svm_fifo_t * f,
-                        int pid, u32 max_bytes, u8 * copy_from_here)
+svm_fifo_enqueue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_from_here)
 {
-  return svm_fifo_enqueue_internal (f, pid, max_bytes, copy_from_here);
+  return svm_fifo_enqueue_internal (f, max_bytes, copy_from_here);
 }
 
 /**
@@ -371,47 +432,48 @@ svm_fifo_enqueue_nowait (svm_fifo_t * f,
  */
 static int
 svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f,
-                                      int pid,
                                       u32 offset,
                                       u32 required_bytes,
                                       u8 * copy_from_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
-  u32 cursize, nitems;
-  u32 tail_plus_offset;
+  u32 cursize, nitems, normalized_offset;
+  u32 offset_from_tail;
 
-  ASSERT (offset > 0);
+  f->ooos_newest = OOO_SEGMENT_INVALID_INDEX;
 
-  /* read cursize, which can only decrease while we're working */
-  cursize = f->cursize;
+  /* read cursize, which can only increase while we're working */
+  cursize = svm_fifo_max_dequeue (f);
   nitems = f->nitems;
 
+  normalized_offset = (f->tail + offset) % nitems;
+
   /* Will this request fit? */
-  if ((required_bytes + offset) > (nitems - cursize))
+  offset_from_tail = (nitems + normalized_offset - f->tail) % nitems;
+  if ((required_bytes + offset_from_tail) > (nitems - cursize))
     return -1;
 
   ooo_segment_add (f, offset, required_bytes);
 
   /* Number of bytes we're going to copy */
   total_copy_bytes = required_bytes;
-  tail_plus_offset = (f->tail + offset) % nitems;
 
   /* Number of bytes in first copy segment */
-  first_copy_bytes = ((nitems - tail_plus_offset) < total_copy_bytes)
-    ? (nitems - tail_plus_offset) : total_copy_bytes;
+  first_copy_bytes = ((nitems - normalized_offset) < total_copy_bytes)
+    ? (nitems - normalized_offset) : total_copy_bytes;
 
-  clib_memcpy (&f->data[tail_plus_offset], copy_from_here, first_copy_bytes);
+  clib_memcpy (&f->data[normalized_offset], copy_from_here, first_copy_bytes);
 
   /* Number of bytes in second copy segment, if any */
   second_copy_bytes = total_copy_bytes - first_copy_bytes;
   if (second_copy_bytes)
     {
-      tail_plus_offset += first_copy_bytes;
-      tail_plus_offset %= nitems;
+      normalized_offset += first_copy_bytes;
+      normalized_offset %= nitems;
 
-      ASSERT (tail_plus_offset == 0);
+      ASSERT (normalized_offset == 0);
 
-      clib_memcpy (&f->data[tail_plus_offset],
+      clib_memcpy (&f->data[normalized_offset],
                   copy_from_here + first_copy_bytes, second_copy_bytes);
     }
 
@@ -421,27 +483,25 @@ svm_fifo_enqueue_with_offset_internal (svm_fifo_t * f,
 
 int
 svm_fifo_enqueue_with_offset (svm_fifo_t * f,
-                             int pid,
                              u32 offset,
                              u32 required_bytes, u8 * copy_from_here)
 {
-  return svm_fifo_enqueue_with_offset_internal
-    (f, pid, offset, required_bytes, copy_from_here);
+  return svm_fifo_enqueue_with_offset_internal (f, offset, required_bytes,
+                                               copy_from_here);
 }
 
 
 static int
-svm_fifo_dequeue_internal (svm_fifo_t * f,
-                          int pid, u32 max_bytes, u8 * copy_here)
+svm_fifo_dequeue_internal (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems;
 
-  if (PREDICT_FALSE (f->cursize == 0))
+  /* read cursize, which can only increase while we're working */
+  cursize = svm_fifo_max_dequeue (f);
+  if (PREDICT_FALSE (cursize == 0))
     return -2;                 /* nothing in the fifo */
 
-  /* read cursize, which can only increase while we're working */
-  cursize = f->cursize;
   nitems = f->nitems;
 
   /* Number of bytes we're going to copy */
@@ -482,30 +542,30 @@ svm_fifo_dequeue_internal (svm_fifo_t * f,
 }
 
 int
-svm_fifo_dequeue_nowait (svm_fifo_t * f,
-                        int pid, u32 max_bytes, u8 * copy_here)
+svm_fifo_dequeue_nowait (svm_fifo_t * f, u32 max_bytes, u8 * copy_here)
 {
-  return svm_fifo_dequeue_internal (f, pid, max_bytes, copy_here);
+  return svm_fifo_dequeue_internal (f, max_bytes, copy_here);
 }
 
 int
-svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
+svm_fifo_peek (svm_fifo_t * f, u32 relative_offset, u32 max_bytes,
               u8 * copy_here)
 {
   u32 total_copy_bytes, first_copy_bytes, second_copy_bytes;
   u32 cursize, nitems, real_head;
 
-  if (PREDICT_FALSE (f->cursize == 0))
+  /* read cursize, which can only increase while we're working */
+  cursize = svm_fifo_max_dequeue (f);
+  if (PREDICT_FALSE (cursize < relative_offset))
     return -2;                 /* nothing in the fifo */
 
-  /* read cursize, which can only increase while we're working */
-  cursize = f->cursize;
   nitems = f->nitems;
-  real_head = f->head + offset;
+  real_head = f->head + relative_offset;
   real_head = real_head >= nitems ? real_head - nitems : real_head;
 
   /* Number of bytes we're going to copy */
-  total_copy_bytes = (cursize < max_bytes) ? cursize : max_bytes;
+  total_copy_bytes = (cursize - relative_offset < max_bytes) ?
+    cursize - relative_offset : max_bytes;
 
   if (PREDICT_TRUE (copy_here != 0))
     {
@@ -527,16 +587,16 @@ svm_fifo_peek (svm_fifo_t * f, int pid, u32 offset, u32 max_bytes,
 }
 
 int
-svm_fifo_dequeue_drop (svm_fifo_t * f, int pid, u32 max_bytes)
+svm_fifo_dequeue_drop (svm_fifo_t * f, u32 max_bytes)
 {
   u32 total_drop_bytes, first_drop_bytes, second_drop_bytes;
   u32 cursize, nitems;
 
-  if (PREDICT_FALSE (f->cursize == 0))
+  /* read cursize, which can only increase while we're working */
+  cursize = svm_fifo_max_dequeue (f);
+  if (PREDICT_FALSE (cursize == 0))
     return -2;                 /* nothing in the fifo */
 
-  /* read cursize, which can only increase while we're working */
-  cursize = f->cursize;
   nitems = f->nitems;
 
   /* Number of bytes we're going to drop */
@@ -562,6 +622,27 @@ svm_fifo_dequeue_drop (svm_fifo_t * f, int pid, u32 max_bytes)
   return total_drop_bytes;
 }
 
+u32
+svm_fifo_number_ooo_segments (svm_fifo_t * f)
+{
+  return pool_elts (f->ooo_segments);
+}
+
+ooo_segment_t *
+svm_fifo_first_ooo_segment (svm_fifo_t * f)
+{
+  return pool_elt_at_index (f->ooo_segments, f->ooos_list_head);
+}
+
+/**
+ * Set fifo pointers to requested offset
+ */
+void
+svm_fifo_init_pointers (svm_fifo_t * f, u32 pointer)
+{
+  f->head = f->tail = pointer % f->nitems;
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *