Messages in this thread | | | Date | Wed, 15 Jan 2014 14:59:30 +0100 | From | Michal Hocko <> | Subject | Re: Notifying on empty cgroup |
| |
[CCing cgroups mailing list] On Wed 15-01-14 06:12:45, Victor Porton wrote: > I want to write software which needs to receive a signal when the cgroup > created by it becomes empty. (After this the empty cgroup should be deleted > just not to clutter the memory.) > > If the kernel does not support such notifications, it should be improved. > This functionality is crucial for some kinds of software. > > There is /sys/fs/cgroup/systemd/release_agent but I don't understand how to > use it. I don't understand why we would need it at all.
"1.4 What does notify_on_release do ?" in Documentation/cgroups/cgroups.txt the kernel source doesn't help?
> Starting a binary on emptying a cgroup with the purpose to notify an other > binary looks like a big overkill.
the binary can do rmdir which is what you want, no?
> Also my program should work in userspace without the need to use > release_agent which can be accessed only by root.
The release_agent is global for all groups so the program doesn't have to care.
> Note that my work is related with sandboxing software (running a program in > closed environment, so that it would be unable for example to remove user's > files). > > See also > http://portonsoft.wordpress.com/2014/01/11/toward-robust-linux-sandbox/ > > -- > Victor Porton - http://portonvictor.org > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- Michal Hocko SUSE Labs
| |