mysqld经常无缘无故挂掉了

重启mysqld没用，找到根本原因吧，分析下/data/mysql/mysql-error.log

2016-04-06 01:57:45 6605 [Note] Plugin 'FEDERATED' is disabled.
2016-04-06 01:57:45 6605 [Note] InnoDB: Using atomics to ref count buffer pool pages
2016-04-06 01:57:45 6605 [Note] InnoDB: The InnoDB memory heap is disabled
2016-04-06 01:57:45 6605 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-04-06 01:57:45 6605 [Note] InnoDB: Memory barrier is not used
2016-04-06 01:57:45 6605 [Note] InnoDB: Compressed tables use zlib 1.2.3
2016-04-06 01:57:45 6605 [Note] InnoDB: Using CPU crc32 instructions
2016-04-06 01:57:45 6605 [Note] InnoDB: Initializing buffer pool, size = 1.0G
InnoDB: mmap(137363456 bytes) failed; errno 12
2016-04-06 01:57:45 6605 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2016-04-06 01:57:45 6605 [ERROR] Plugin 'InnoDB' init function returned error.
2016-04-06 01:57:45 6605 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2016-04-06 01:57:45 6605 [ERROR] Unknown/unsupported storage engine: InnoDB
2016-04-06 01:57:45 6605 [ERROR] Aborting

大大，这种情况我应该怎么调整呢

[root@localhost ~]# free -ml
total used free shared buffers cached
Mem: 3998 3030 968 23 20 260
Low: 3998 3030 968
High: 0 0 0
-/+ buffers/cache: 2748 1249
Swap: 511 199 312

调小。。/etc/my.cnf innodb相关参数