!2988 [sync] PR-1203: Revert "locking/rwsem: Prevent potential lock starvation"

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1203 
 
PR sync from: Zheng Zengkai <zhengzengkai@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/RDUNFZSP4CQYRI7TDPSAJZDZEHHQL3H3/ 
2f06f702 ("locking/rwsem: Prevent potential lock starvation"):
This patch may have some impact on reader performance as it reduces
reader optimistic spinning especially if the lock critical sections
are short the number of contending readers are small.

This patch will lead to 30%+ performance degradation to fio write_iops_blocksize
4KB testcase, and we stress the system with mysql tpcc for 12 hours,
no hungtask occur, So revert this patchset temporarily. 
 
Link:https://gitee.com/openeuler/kernel/pulls/2988

 

Reviewed-by: Zheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>