Merge lp:~tplavcic/percona-server/bug1382069-5.6 into lp:percona-server/5.6

[Tomislav Plavcic]

Mysqld_safe was loading system jemalloc if installed no matter if user specified another malloc lib - so it was possible that it tries to load 2 libs. Also there was no possibility to disable loading of system jemalloc.
With this change system jemalloc is only loaded if no other lib is specified and if user specifies "malloc-lib=" nothing will be loaded.

Param job is here:
http://jenkins.percona.com/view/PS%205.6/job/percona-server-5.6-param/742/

Some testing:
TEST1: nothing in my.cnf (automatically loads system jemalloc)
======
vagrant@t-ubuntu14:~$ sudo /usr/bin/mysqld_safe
141021 00:47:57 mysqld_safe Adding '/usr/lib/x86_64-linux-gnu/libjemalloc.so.1' to LD_PRELOAD for mysqld
141021 00:47:57 mysqld_safe Logging to '/var/log/mysql/error.log'.
141021 00:47:57 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

TEST2: malloc-lib= (loads nothing)
======
vagrant@t-ubuntu14:~$ sudo /usr/bin/mysqld_safe
141021 00:54:35 mysqld_safe Logging to '/var/log/mysql/error.log'.
141021 00:54:35 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

TEST3: malloc-lib=/home/vagrant/ps/lib/mysql/libjemalloc.so.1 (loads only specified lib)
======
vagrant@t-ubuntu14:~$ sudo /usr/bin/mysqld_safe
141021 00:55:57 mysqld_safe Adding '/home/vagrant/ps/lib/mysql/libjemalloc.so.1' to LD_PRELOAD for mysqld
141021 00:55:57 mysqld_safe Logging to '/var/log/mysql/error.log'.
141021 00:55:57 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

[Laurynas Biveinis (laurynas-biveinis)]

review: Approve

=== modified file 'scripts/mysqld_safe.sh'
--- scripts/mysqld_safe.sh	2014-05-13 20:23:41 +0000
+++ scripts/mysqld_safe.sh	2014-10-21 08:13:52 +0000
@@ -17,6 +17,7 @@
 niceness=0
 mysqld_ld_preload=
 mysqld_ld_library_path=
+load_jemalloc=1
 flush_caches=0
 numa_interleave=0
 
@@ -214,7 +215,10 @@
       # mysqld_safe-specific options - must be set in my.cnf ([mysqld_safe])!
       --core-file-size=*) core_file_size="$val" ;;
       --ledir=*) ledir="$val" ;;
-      --malloc-lib=*) set_malloc_lib "$val" ;;
+      --malloc-lib=*)
+	set_malloc_lib "$val"
+	load_jemalloc=0
+	;;
       --mysqld=*) MYSQLD="$val" ;;
       --mysqld-version=*)
         if test -n "$val"
@@ -375,19 +379,6 @@
 
 
 #
-# Add jemalloc to ld_preload - needed for TokuDB
-#
-for libjemall in "/usr/lib64" "/usr/lib/x86_64-linux-gnu" "/usr/lib"
-do
-if test -f "$libjemall/libjemalloc.so.1"
-then
-  add_mysqld_ld_preload "$libjemall/libjemalloc.so.1"
-  break
-fi
-done
-
-
-#
 # First, try to find BASEDIR and ledir (where mysqld is)
 #
 
@@ -517,6 +508,19 @@
 parse_arguments PICK-ARGS-FROM-ARGV "$@"
 
 #
+# Add jemalloc to ld_preload if no other malloc forced - needed for TokuDB
+#
+if test $load_jemalloc -eq 1
+then
+  for libjemall in "/usr/lib64" "/usr/lib/x86_64-linux-gnu" "/usr/lib"; do
+    if [ -r "$libjemall/libjemalloc.so.1" ]; then
+      add_mysqld_ld_preload "$libjemall/libjemalloc.so.1"
+      break
+    fi  
+  done
+fi
+
+#
 # Try to find the plugin directory
 #