* [QUESTION]cgroup mount return -EBUSY
@ 2024-04-26 4:55 Lu Jialin
2024-05-06 1:50 ` Lu Jialin
0 siblings, 1 reply; 2+ messages in thread
From: Lu Jialin @ 2024-04-26 4:55 UTC (permalink / raw)
To: Tejun Heo, Zefan Li, Johannes Weiner; +Cc: cgroups, linux-kernel
Hello
I encountered a problem when I try to unmount the subsystem right after
all it's subcgroups are removed, the cgroup_root would remain. Mounting
this subsystem to another cgroup_root would return -EBUSY.
The problem could be reproduced with the following script.
test.sh:
mkdir /tmp/test1
mount -t cgroup -o pids pids /tmp/test1
mkdir /tmp/test1/test
rmdir /tmp/test1/test
umount /tmp/test1
mkdir /tmp/test
mount -t cgroup -o pids,cpu none /tmp/test
test.sh should return this.
mount: mounting none on /tmp/test failed: Device or resource busy.
It seems that when unmounting /tmp/test1, the original cgroup_root for
this PID is not released.
/test # cat /proc/cgroups
#subsys_name hierarchy num_cgroups enabled
cpuset 0 1 1
cpu 0 1 1
cpuacct 0 1 1
blkio 0 1 1
devices 0 1 1
freezer 0 1 1
net_cls 0 1 1
perf_event 0 1 1
net_prio 0 1 1
hugetlb 0 1 1
pids 1 1 1
rdma 0 1 1
misc 0 1 1
debug 0 1 1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [QUESTION]cgroup mount return -EBUSY
2024-04-26 4:55 [QUESTION]cgroup mount return -EBUSY Lu Jialin
@ 2024-05-06 1:50 ` Lu Jialin
0 siblings, 0 replies; 2+ messages in thread
From: Lu Jialin @ 2024-05-06 1:50 UTC (permalink / raw)
To: Tejun Heo, Zefan Li, Johannes Weiner; +Cc: cgroups, linux-kernel
ping
On 2024/4/26 12:55, Lu Jialin wrote:
> Hello
>
> I encountered a problem when I try to unmount the subsystem right after
> all it's subcgroups are removed, the cgroup_root would remain. Mounting
> this subsystem to another cgroup_root would return -EBUSY.
>
> The problem could be reproduced with the following script.
>
> test.sh:
>
> mkdir /tmp/test1
> mount -t cgroup -o pids pids /tmp/test1
> mkdir /tmp/test1/test
> rmdir /tmp/test1/test
> umount /tmp/test1
> mkdir /tmp/test
> mount -t cgroup -o pids,cpu none /tmp/test
>
> test.sh should return this.
> mount: mounting none on /tmp/test failed: Device or resource busy.
>
> It seems that when unmounting /tmp/test1, the original cgroup_root for
> this PID is not released.
> /test # cat /proc/cgroups
>
> #subsys_name hierarchy num_cgroups enabled
>
> cpuset 0 1 1
>
> cpu 0 1 1
>
> cpuacct 0 1 1
>
> blkio 0 1 1
>
> devices 0 1 1
>
> freezer 0 1 1
>
> net_cls 0 1 1
>
> perf_event 0 1 1
>
> net_prio 0 1 1
>
> hugetlb 0 1 1
>
> pids 1 1 1
>
> rdma 0 1 1
>
> misc 0 1 1
>
> debug 0 1 1
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2024-05-06 1:50 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-04-26 4:55 [QUESTION]cgroup mount return -EBUSY Lu Jialin
2024-05-06 1:50 ` Lu Jialin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).