Hi，非常感谢给予这么多好的建议。但是这个补丁还不需要合入，如下说明：

commit 385aac1519417b89cb91b77c22e4ca21db563cd0
Author: Odin Ugedal <odin@uged.al>
Date:   Sat Jan 16 18:36:33 2021 +0100

    cgroup: fix psi monitor for root cgroup

    Fix NULL pointer dereference when adding new psi monitor to the root
    cgroup. PSI files for root cgroup was introduced in df5ba5be742 by using
    system wide psi struct when reading, but file write/monitor was not
    properly fixed.

    对cgroup文件写的时候会触发NULL指针，而目前的patches没有合入cgroup文件的写和poll monitor的patch。

    Since the PSI config for the root cgroup isn't
    initialized, the current implementation tries to lock a NULL ptr,
    resulting in a crash.

    Can be triggered by running this as root:
    $ tee /sys/fs/cgroup/cpu.pressure <<< "some 10000 1000000"

    Signed-off-by: Odin Ugedal <odin@uged.al>
    Reviewed-by: Suren Baghdasaryan <surenb@google.com>
    Acked-by: Dan Schatzberg <dschatzberg@fb.com>
    Fixes: df5ba5be7425 ("kernel/sched/psi.c: expose pressure metrics on root cgroup")
    Acked-by: Johannes Weiner <hannes@cmpxchg.org>
    Cc: stable@vger.kernel.org # 5.2+
    Signed-off-by: Tejun Heo <tj@kernel.org>



------------------ 原始邮件 ------------------  

发件人："chengjian （D）" "cj.chengjian@huawei.com"  
时　间：2021/10/16 11:09:07 星期六  
收件人：Liu Xinpeng "liuxp11@chinatelecom.cn", kernel@openeuler.org  
抄送人：xiexiuqi@huawei.com, "chengjian （D）" "cj.chengjian@huawei.com", qiulaibin@huawei.com, Li Bin "huawei.libin@huawei.com"  
主　题：Re: [PATCH kernel-4.19 v4 19/22] kernel/sched/psi.c: expose pressure metrics on root cgroup  

hi，新朋：    

这个补丁检查出有一个 fix 补丁，麻烦一次合入下。    

谢谢。    

WARNING: **NEW BUGFIX** may exists in mainline kernel    

git log --grep "df5ba5be7425" --grep "kernel/sched/psi.c: expose    
pressure metrics on root cgroup"    

new fix: 385aac151941 ("cgroup: fix psi monitor for root cgroup")    

在 2021/10/15 16:21, Liu Xinpeng 写道:    
> From: Dan Schatzberg