Отсутствуют функции PHP libevent

Я установил библиотеку php-pecl-event, но не вижу никаких функций библиотеки:

[root@server ~]# php -r "var_dump(function_exists('event_free'));"
bool(false)
[root@server ~]# php -r "var_dump(function_exists('event_add'));"
bool(false)
[root@server ~]# php -r "var_dump(function_exists('event_buffer_free'));"
bool(false)

Я установил следующие пакеты:

[root@server ~]# pecl list
Installed packages, channel pecl.php.net:
=========================================
Package   Version   State
APC       3.1.15dev beta
event     1.10.2    stable
jsonc     1.3.4     stable
memcache  3.0.8     beta
memcached 2.2.0     stable
msgpack   0.5.5     beta
zip       1.12.4    stable
zmq       1.1.2     beta


[root@server ~]# php-config
Usage: /usr/bin/php-config [OPTION]
Options:
  --prefix            [/usr]
  --includes          [-I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib]
  --ldflags           []
  --libs              [-lcrypt   -lcrypt -ledit -lncurses -lstdc++ -lz -lrt -lm -ldl -lnsl  -lxml2 -lz -lm -lgssapi_krb5 -lkrb5 -lk5crypto -lcom_err -lssl -lcrypto -lcrypt -lcrypt ]
  --extension-dir     [/usr/lib64/php/modules]
  --include-dir       [/usr/include/php]
  --man-dir           [/usr/share/man]
  --php-binary        [/usr/bin/php]
  --php-sapis         [ cli cgi]
  --configure-options [--build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --target=x86_64-redhat-linux-gnu --program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --cache-file=../config.cache --with-libdir=lib64 --with-config-file-path=/etc --with-config-file-scan-dir=/etc/php.d --disable-debug --with-pic --disable-rpath --without-pear --with-exec-dir=/usr/bin --with-freetype-dir=/usr --with-png-dir=/usr --with-xpm-dir=/usr --enable-gd-native-ttf --with-t1lib=/usr --without-gdbm --with-jpeg-dir=/usr --with-openssl --with-zlib --with-layout=GNU --with-kerberos --with-libxml-dir=/usr --with-system-tzdata --with-mhash --enable-dtrace --libdir=/usr/lib64/php --enable-pcntl --enable-opcache --with-imap=shared --with-imap-ssl --enable-mbstring=shared --enable-mbregex --with-gd=shared,/usr --with-gmp=shared --enable-calendar=shared --enable-bcmath=shared --with-bz2=shared --enable-ctype=shared --enable-dba=shared --with-db4=/usr --with-gdbm=/usr --with-tcadb=/usr --enable-exif=shared --enable-ftp=shared --with-gettext=shared --with-iconv=shared --enable-sockets=shared --enable-tokenizer=shared --with-xmlrpc=shared --with-ldap=shared --with-ldap-sasl --enable-mysqlnd=shared --with-mysql=shared,mysqlnd --with-mysqli=shared,mysqlnd --with-mysql-sock=/var/lib/mysql/mysql.sock --with-oci8=shared,instantclient,/usr/lib64/oracle/12.1/client64/lib,12.1 --with-pdo-oci=shared,instantclient,/usr,12.1 --with-interbase=shared,/usr/lib64/firebird --with-pdo-firebird=shared,/usr/lib64/firebird --enable-dom=shared --with-pgsql=shared --enable-simplexml=shared --enable-xml=shared --enable-wddx=shared --with-snmp=shared,/usr --enable-soap=shared --with-xsl=shared,/usr --enable-xmlreader=shared --enable-xmlwriter=shared --with-curl=shared,/usr --enable-pdo=shared --with-pdo-odbc=shared,unixODBC,/usr --with-pdo-mysql=shared,mysqlnd --with-pdo-pgsql=shared,/usr --with-pdo-sqlite=shared,/usr --with-pdo-dblib=shared,/usr --with-sqlite3=shared,/usr --without-readline --with-libedit --with-pspell=shared --enable-phar=shared --with-mcrypt=shared,/usr --with-tidy=shared,/usr --with-mssql=shared,/usr --enable-sysvmsg=shared --enable-sysvshm=shared --enable-sysvsem=shared --enable-shmop=shared --enable-posix=shared --with-unixODBC=shared,/usr --enable-fileinfo=shared --enable-intl=shared --with-icu-dir=/usr --with-enchant=shared,/usr --with-recode=shared,/usr]
  --version           [5.5.11]
  --vernum            [50511]

А это раздел из php -i:

event

Event support => enabled
Sockets support => enabled
Debug support => disabled
Extra functionality support including HTTP, DNS, and RPC => enabled
OpenSSL support => enabled
Thread safety support => disabled
Extension version => 1.10.2
libevent2 headers version => 2.0.21-stable

Кто-нибудь знает о недостающих функциях?