Compile with jemalloc to reduce memory allocator contention

The jemalloc allocator is scalable high performance allocator, this is
the first in the series of commits that will add jemalloc as a memory
allocator for BIND 9.

This commit adds configure.ac check and Makefile modifications to use
jemalloc as BIND 9 allocator.

configure.ac

@@ -1376,6 +1376,17 @@ AC_SUBST([CMOCKA_LIBS])
 
 AM_CONDITIONAL([HAVE_CMOCKA], [test "$with_cmocka" = "yes"])
 
+#
+#
+#
+AC_MSG_CHECKING([for jemalloc])
+PKG_CHECK_MODULES([JEMALLOC], [jemalloc >= 5], []
+		  [AC_MSG_WARN([Using jemalloc 5 is recommended])
+		   PKG_CHECK_MODULES([JEMALLOC], [jemalloc], [],
+				     [AC_MSG_ERROR([jemalloc not found])])])
+AC_SUBST([JEMALLOC_CFLAGS])
+AC_SUBST([JEMALLOC_LIBS])
+
 #
 # was --with-tuning specified?
 #

lib/isc/Makefile.am

@@ -230,6 +230,7 @@ libisc_la_SOURCES =		\
 
 libisc_la_CPPFLAGS =		\
 	$(AM_CPPFLAGS)		\
+	$(JEMALLOC_CPPFLAGS)	\
 	$(LIBISC_CFLAGS)	\
 	$(LIBUV_CFLAGS)		\
 	$(OPENSSL_CFLAGS)	\
@@ -240,6 +241,7 @@ libisc_la_LDFLAGS =		\
 	-release "$(PACKAGE_VERSION)"
 
 libisc_la_LIBADD =		\
+	$(JEMALLOC_LIBS)	\
 	$(LIBUV_LIBS)		\
 	$(OPENSSL_LIBS)		\
 	$(ZLIB_LIBS)