From a36aea827b76b19c82b780de0762da30c230f19f Mon Sep 17 00:00:00 2001
From: Todd Lipcon <todd@cloudera.com>
Date: Tue, 23 Sep 2014 19:09:56 -0700
Subject: [PATCH] Change default TCMALLOC_TRANSFER_NUM_OBJ to 40

We found that this configuration was preventing good performance
of the central freelist in benchmarks with a lot of threads.

After discussion with Aliaksey Kandratsenka (the gperftools maintainer)
we decided the best course of action was to revert to a number close to the old
default, which seems to improve the performance of these high-concurrency
benchmarks by about 4.5x.

Any higher numbers seem to produce worse performance in our benchmarks.
---
 src/common.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/common.cc b/src/common.cc
index 9d48377..c2ad054 100644
--- a/src/common.cc
+++ b/src/common.cc
@@ -42,7 +42,7 @@ namespace tcmalloc {
 // thread and central caches.
 static int32 FLAGS_tcmalloc_transfer_num_objects;
 
-static const int32 kDefaultTransferNumObjecs = 32768;
+static const int32 kDefaultTransferNumObjecs = 40;
 
 // The init function is provided to explicit initialize the variable value
 // from the env. var to avoid C++ global construction that might defer its
-- 
1.8.3.2