[ERROR] InnoDB: Cannot allocate memory for the buffer pool

2018-05-07 01:17:43 3327 [Note] Plugin 'FEDERATED' is disabled.
2018-05-07 01:17:43 7f4912cf4740 InnoDB: Warning: Using innodb_additional_mem_pool_size is DEPRECATED. This option may be removed in future releases, together with the option innodb_use_sys_malloc and with the InnoDB's internal memory allocator.
2018-05-07 01:17:43 3327 [Note] InnoDB: Using atomics to ref count buffer pool pages
2018-05-07 01:17:43 3327 [Note] InnoDB: The InnoDB memory heap is disabled
2018-05-07 01:17:43 3327 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2018-05-07 01:17:43 3327 [Note] InnoDB: Memory barrier is not used
2018-05-07 01:17:43 3327 [Note] InnoDB: Compressed tables use zlib 1.2.3
2018-05-07 01:17:43 3327 [Note] InnoDB: Using Linux native AIO
2018-05-07 01:17:43 3327 [Note] InnoDB: Using CPU crc32 instructions
2018-05-07 01:17:43 3327 [Note] InnoDB: Initializing buffer pool, size = 80.0G
InnoDB: mmap(10989076480 bytes) failed; errno 12
2018-05-07 01:17:43 3327 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2018-05-07 01:17:43 3327 [ERROR] Plugin 'InnoDB' init function returned error.
2018-05-07 01:17:43 3327 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2018-05-07 01:17:43 3327 [ERROR] Unknown/unsupported storage engine: InnoDB
2018-05-07 01:17:43 3327 [ERROR] Aborting

服务器开启了一个任务，比较消耗资源，而服务器上的 mysql 意外宕机了，error日志描述如山所示：

[ERROR] InnoDB: Cannot allocate memory for the buffer pool

使用free  -g查看到当前系统可用内存只有6g了

而检查my.cnf配置文件，里面的buffer_pool是

innodb_buffer_pool_size=64G

估计当前可用内存不够了，所以down机了，开启的任务不好停止，把innodb_buffer_pool_size的配置改成1G，重启下mysql服务，问题解决。