!3638 memcg: support OOM priority for memcg

Merge Pull Request from: @ci-robot 
 
PR sync from: Jinjiang Tu <tujinjiang@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/YMPERNQUGIRDCEWEYZRCHXDGAQHSCESX/ 
Support memcg oom priority.

Changelog:
* rename CONFIG_MEMCG_QOS to CONFIG_MEMCG_OOM_PRIORITY
* move CONFIG_MEMCG_OOM_PRIORITY to init/Kconfig
* set CONFIG_MEMCG_OOM_PRIORITY default from y to n, and enable it in openeuler_defconfig
* add rcu_read_lock() protection for mem_cgroup_from_task()
* Instead of static key, use variable to check if the feature is enabled
* use READ_ONCE/WRITE_ONCE protection when read/write oom_prio
* cleanup

Jing Xiangfeng (3):
  memcg: support priority for oom
  memcg: Add sysctl memcg_qos_enable
  memcg: enable CONFIG_MEMCG_OOM_PRIORITY by default


-- 
2.25.1
 
https://gitee.com/openeuler/kernel/issues/I8PXX8 
 
Link:https://gitee.com/openeuler/kernel/pulls/3638

 

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Lu Jialin <lujialin4@huawei.com>
Reviewed-by: Liu Chao <liuchao173@huawei.com>
Reviewed-by: Zhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>