设置了low_priority_updates却依然会被system lock

[netxuning]

我想让系统读优先，所以将low_priority_updates设置为on,主服务器生效，写操作会靠后。
但是在slave上却不然，还是被同步的写锁住，也就是被replication进程System lock。
这有没有啥解决的办法？

[军爷_010]

If set to 1, all INSERT, UPDATE, DELETE, and LOCK TABLE WRITE statements wait until there is no pending SELECT or LOCK TABLE READ on the affected table. This affects only storage engines that use only table-level locking (MyISAM, MEMORY, MERGE). This variable previously was named sql_low_priority_updates.