Hi Christian,
Thank you for writing this!
On 4/10/20 12:41 PM, Christian Brauner wrote:
> From: Christian Brauner <christian.brauner@xxxxxxxxxx>
>
> Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
> ---
> man2/clone.2 | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/man2/clone.2 b/man2/clone.2
> index 39cec4c86..8d9aa9f99 100644
> --- a/man2/clone.2
> +++ b/man2/clone.2
> @@ -197,6 +197,7 @@ struct clone_args {
> u64 tls; /* Location of new TLS */
> u64 set_tid; /* Pointer to a \fIpid_t\fP array */
> u64 set_tid_size; /* Number of elements in \fIset_tid\fP */
> + u64 cgroup; /* Target cgroup file descriptor for the child process */
> };
> .EE
> .in
> @@ -448,6 +449,25 @@ Specifying this flag together with
> .B CLONE_SIGHAND
> is nonsensical and disallowed.
> .TP
> +.BR CLONE_INTO_CGROUP " (since Linux 5.7)"
> +.\" commit ef2c41cf38a7559bbf91af42d5b6a4429db8fc68
> +By default, the child process will belong to the same cgroup as its parent.
s/belong to/be placed in/
s/cgroup/version 2 cgroup/
> +If this flag is specified the child process will be created in a
> +different cgroup than its parent.
> +
> +When using
> +.RB clone3 ()
> +the target cgroup can be specified by setting the
> +.I cl_args.cgroup
> +member to the file descriptor of the target cgroup. The cgroup file
We need to say something about how this file descriptor is
obtained. Is it by opening a directory in the v2 cgroup hierarchy?
With what flags? O_RDONLY? or is O_PATH also possible? Yes, these
are some rhetorical questions (I read your nice commit message);
these things need to be explicit in the manual page though.
Also, your commit message mentions a nice list of use cases.
I think it would be well worth capturing those in a paragraph
in the manual page text.
> +descriptor must refer to a cgroup in a cgroup v2 hierarchy
> +(see
> +.BR cgroup (2)).
s/cgroup/cgroups/
s/2/7/
> +
> +Note that all usual cgroup v2 process migration restrictions apply. See
> +.BR cgroup (2)
s/cgroup/cgroups/
s/2/7/
Thanks,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
