svm: minimal initial fifo

Type: refactor

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I4ee46a6c3c53c58199c275e20702f7fd11b60d9a

3 files changed, 12 insertions, 11 deletions

diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index 88600b84e36..7b1163e0750 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -294,8 +294,7 @@ fs_chunk_size_is_valid (fifo_segment_header_t * fsh, u32 size)
 }
 
 static svm_fifo_t *
-fs_try_alloc_fifo_freelist (fifo_segment_slice_t * fss,
-			    u32 fl_index, u32 data_bytes)
+fs_try_alloc_fifo_freelist (fifo_segment_slice_t * fss, u32 fl_index)
 {
   svm_fifo_chunk_t *c;
   svm_fifo_t *f;
@@ -471,14 +470,16 @@ fs_try_alloc_fifo (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;
 
-  fl_index = fs_freelist_for_size (data_bytes);
+  min_size = clib_max ((fsh->pct_first_alloc * data_bytes) / 100, 4096);
+  fl_index = fs_freelist_for_size (min_size);
   fifo_sz = sizeof (svm_fifo_t) + sizeof (svm_fifo_chunk_t);
-  fifo_sz += 1 << max_log2 (data_bytes);
+  fifo_sz += 1 << max_log2 (min_size);
 
   if (fss->free_fifos && fss->free_chunks[fl_index])
     {
-      f = fs_try_alloc_fifo_freelist (fss, fl_index, data_bytes);
+      f = fs_try_alloc_fifo_freelist (fss, fl_index);
       if (f)
 	{
 	  fsh_cached_bytes_sub (fsh, fs_freelist_index_to_size (fl_index));
@@ -494,7 +495,7 @@ fs_try_alloc_fifo (fifo_segment_header_t * fsh, fifo_segment_slice_t * fss,
 				   FIFO_SEGMENT_ALLOC_BATCH_SIZE))
 	goto done;
 
-      f = fs_try_alloc_fifo_freelist (fss, fl_index, data_bytes);
+      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;
@@ -502,7 +503,7 @@ fs_try_alloc_fifo (fifo_segment_header_t * fsh, fifo_segment_slice_t * fss,
   if (fifo_sz <= n_free_bytes)
     {
       void *oldheap = ssvm_push_heap (fsh->ssvm_sh);
-      f = svm_fifo_alloc (data_bytes);
+      f = svm_fifo_alloc (min_size);
       ssvm_pop_heap (oldheap);
       if (f)
 	{
diff --git a/src/svm/fifo_types.h b/src/svm/fifo_types.h
index f0a286d46a0..a80130b0e92 100644
--- a/src/svm/fifo_types.h
+++ b/src/svm/fifo_types.h
@@ -120,6 +120,7 @@ struct fifo_segment_header_
   u8 n_slices;				/**< Number of slices */
   u8 high_watermark;			/**< Memory pressure watermark high */
   u8 low_watermark;			/**< Memory pressure watermark low */
+  u8 pct_first_alloc;			/**< Pct of fifo size to alloc */
 };
 
 #endif /* SRC_SVM_FIFO_TYPES_H_ */
diff --git a/src/svm/svm_fifo.c b/src/svm/svm_fifo.c
index 0168c08e49c..971eda351d5 100644
--- a/src/svm/svm_fifo.c
+++ b/src/svm/svm_fifo.c
@@ -368,7 +368,7 @@ void
 svm_fifo_init (svm_fifo_t * f, u32 size)
 {
   svm_fifo_chunk_t *c, *prev;
-  u32 first_chunk, min_alloc;
+  u32 min_alloc;
 
   f->size = size;
   f->ooos_list_head = OOO_SEGMENT_INVALID_INDEX;
@@ -378,9 +378,8 @@ svm_fifo_init (svm_fifo_t * f, u32 size)
   f->head_chunk = f->tail_chunk = f->start_chunk;
   f->ooo_deq = f->ooo_enq = 0;
 
-  first_chunk = f->start_chunk->length;
-  min_alloc = first_chunk > 16 << 10 ? first_chunk >> 2 : 4096;
-  min_alloc = clib_min (first_chunk, 64 << 10);
+  min_alloc = size > 32 << 10 ? size >> 3 : 4096;
+  min_alloc = clib_min (min_alloc, 64 << 10);
   f->min_alloc = min_alloc;
 
   /*