[Bf-blender-cvs] [7cb90a6] master: Optimization for mempool initial chunk allocation

[Campbell Barton]

Commit: 7cb90a611faa506d7576f1f27f42be6936a45f5e
Author: Campbell Barton
Date:   Fri Apr 4 21:20:17 2014 +1100
https://developer.blender.org/rB7cb90a611faa506d7576f1f27f42be6936a45f5e

Optimization for mempool initial chunk allocation

Almost all pools allocated 2 chunks on initialization,
every element needed to be added to the free-list which
would never be used for small pools.

Now allocate only one, gives minor speedup for some bmesh operations.

===================================================================

M	source/blender/blenlib/intern/BLI_mempool.c

===================================================================

diff --git a/source/blender/blenlib/intern/BLI_mempool.c b/source/blender/blenlib/intern/BLI_mempool.c
index 7dc43bb..a37a778 100644
--- a/source/blender/blenlib/intern/BLI_mempool.c
+++ b/source/blender/blenlib/intern/BLI_mempool.c
@@ -121,10 +121,14 @@ struct BLI_mempool {
 
 /**
  * \return the number of chunks to allocate based on how many elements are needed.
+ *
+ * \note for small pools 1 is a good default, the elements need to be initialized,
+ * adding overhead on creation which is redundant if they aren't used.
+ *
  */
 BLI_INLINE unsigned int mempool_maxchunks(const unsigned int totelem, const unsigned int pchunk)
 {
-	return totelem / pchunk + 1;
+	return (totelem <= pchunk) ? 1 : ((totelem / pchunk) + 1);
 }
 
 static BLI_mempool_chunk *mempool_chunk_alloc(BLI_mempool *pool)