Reduce malloc()/free() usage in InnoDB

show processlist;

+-----+--------+--------------------+-------------------+---------+------+------------------+------------------+----------+

| Id  | User   | Host               | db                | Command | Time | State            | Info             | Progress |

+-----+--------+--------------------+-------------------+---------+------+------------------+------------------+----------+

|  85 | loader | 10.10.16.216:43971 | phonebook_storage | Killed  | 1845 | Unlocking tables | NULL             |    0.000 |

| 184 | root   | localhost          | NULL              | Query   |    0 | init             | show processlist |    0.000 |

+-----+--------+--------------------+-------------------+---------+------+------------------+------------------+----------+

# strace -ff -p 33080

...

[pid 60412] madvise(0x7f36cb638000, 331776, MADV_DONTNEED) = 0

[pid 60412] madvise(0x7f36cb441000, 135168, MADV_DONTNEED) = 0

[pid 60412] madvise(0x7f36cb638000, 335872, MADV_DONTNEED) = 0

[pid 60412] madvise(0x7f36cb441000, 135168, MADV_DONTNEED) = 0

[pid 60412] madvise(0x7f36cb638000, 335872, MADV_DONTNEED) = 0

[pid 60412] madvise(0x7f36cb441000, 135168, MADV_DONTNEED) = 0

[pid 60412] madvise(0x7f36cb638000, 335872, MADV_DONTNEED) = 0

/*!40101 SET @saved_cs_client     = @@character_set_client */;

/*!40101 SET character_set_client = utf8 */;

CREATE TABLE `contact` (

  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,

  `id_phonebook` int(10) unsigned NOT NULL DEFAULT '0',

  `id_user` int(10) unsigned NOT NULL DEFAULT '0',

  `firstname` varchar(255) NOT NULL DEFAULT '',

  `lastname` varchar(255) NOT NULL DEFAULT '',

  `local_key` varchar(255) NOT NULL DEFAULT '',

  PRIMARY KEY (`id`),

  KEY `id_phonebook` (`id_phonebook`) USING BTREE,

  KEY `id_user` (`id_user`) USING BTREE

) ENGINE=InnoDB AUTO_INCREMENT=133028725 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=2;

/*!40101 SET character_set_client = @saved_cs_client */;