kernel.shmmax = 68719476736 单个共享内存段的最大尺寸,设置为物理内存的 50%
kernel.shmall = 4294967296 控制共享内存页数
mysql> select 68719476736/1024/1204/1204;
+----------------------------+
| 68719476736/1024/1204/1204 |
+----------------------------+
| 46.294235162967 |
+----------------------------+
1 row in set (0.00 sec)
mysql> select 4294967296*16/1024/1024/1024; innodb page_size 为 16K
+------------------------------+
| 4294967296*16/1024/1024/1024 |
+------------------------------+
| 64.000000000000 |
+------------------------------+
1 row in set (0.00 sec)