svm: fix inadequate atomic load for chunk mgr

[vpp.git] / src / svm / fifo_segment.c

diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index 3e728ec..cb1f08a 100644 (file)
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -154,7 +154,7 @@ fss_chunk_free_list_push (fifo_segment_header_t *fsh,
 
   csp = fs_chunk_sptr (fsh, c);
   ASSERT (csp <= FS_CL_HEAD_MASK);
-  old_head = clib_atomic_load_relax_n (&fss->free_chunks[fl_index]);
+  old_head = clib_atomic_load_acq_n (&fss->free_chunks[fl_index]);
 
   do
     {
@@ -174,7 +174,7 @@ fss_chunk_free_list_push_list (fifo_segment_header_t *fsh,
 
   headsp = fs_chunk_sptr (fsh, head);
   ASSERT (headsp <= FS_CL_HEAD_MASK);
-  old_head = clib_atomic_load_relax_n (&fss->free_chunks[fl_index]);
+  old_head = clib_atomic_load_acq_n (&fss->free_chunks[fl_index]);
 
   do
     {
@@ -194,7 +194,7 @@ fss_chunk_free_list_pop (fifo_segment_header_t *fsh, fifo_segment_slice_t *fss,
 
   ASSERT (fss_chunk_fl_index_is_valid (fss, fl_index));
 
-  old_head = clib_atomic_load_relax_n (&fss->free_chunks[fl_index]);
+  old_head = clib_atomic_load_acq_n (&fss->free_chunks[fl_index]);
 
   /* Lock-free stacks are affected by ABA if a side allocates a chunk and
    * shortly thereafter frees it. To circumvent that, reuse the upper bits
@@ -694,7 +694,8 @@ free_list:
       if (data_bytes <= fss_fl_chunk_bytes (fss) + n_free)
        {
          u32 min_size = FIFO_SEGMENT_MIN_FIFO_SIZE;
-
+         if (n_free < min_size)
+           goto done;
          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))
@@ -1038,6 +1039,30 @@ fifo_segment_fifo_offset (svm_fifo_t *f)
   return (u8 *) f->shr - (u8 *) f->fs_hdr;
 }
 
+svm_fifo_chunk_t *
+fifo_segment_alloc_chunk_w_slice (fifo_segment_t *fs, u32 slice_index,
+                                 u32 chunk_size)
+{
+  fifo_segment_header_t *fsh = fs->h;
+  fifo_segment_slice_t *fss;
+
+  fss = fsh_slice_get (fsh, slice_index);
+  return fsh_try_alloc_chunk (fsh, fss, chunk_size);
+}
+
+void
+fifo_segment_collect_chunk (fifo_segment_t *fs, u32 slice_index,
+                           svm_fifo_chunk_t *c)
+{
+  fsh_collect_chunks (fs->h, slice_index, c);
+}
+
+uword
+fifo_segment_chunk_offset (fifo_segment_t *fs, svm_fifo_chunk_t *c)
+{
+  return (u8 *) c - (u8 *) fs->h;
+}
+
 svm_msg_q_t *
 fifo_segment_msg_q_alloc (fifo_segment_t *fs, u32 mq_index,
                          svm_msg_q_cfg_t *cfg)