Re: [PATCH] memcg: net: track network throttling due to memcg memory pressure

[Roman Gushchin <roman.gushchin@linux.dev>]

Shakeel Butt <shakeel.butt@linux.dev> writes:

> The kernel can throttle network sockets if the memory cgroup associated
> with the corresponding socket is under memory pressure. The throttling
> actions include clamping the transmit window, failing to expand receive
> or send buffers, aggressively prune out-of-order receive queue, FIN
> deferred to a retransmitted packet and more. Let's add memcg metric to
> indicate track such throttling actions.
>
> At the moment memcg memory pressure is defined through vmpressure and in
> future it may be defined using PSI or we may add more flexible way for
> the users to define memory pressure, maybe through ebpf. However the
> potential throttling actions will remain the same, so this newly
> introduced metric will continue to track throttling actions irrespective
> of how memcg memory pressure is defined.
>
> Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
> ---
>  Documentation/admin-guide/cgroup-v2.rst | 4 ++++
>  include/linux/memcontrol.h              | 1 +
>  include/net/sock.h                      | 6 +++++-
>  kernel/cgroup/cgroup.c                  | 1 +
>  mm/memcontrol.c                         | 3 +++
>  5 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index 0e6c67ac585a..057ee95e43ef 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -1515,6 +1515,10 @@ The following nested keys are defined.
>            oom_group_kill
>                  The number of times a group OOM has occurred.
>  
> +          socks_throttled
> +                The number of times network sockets associated with
> +                this cgroup are throttled.

I'd prefer sockets_throttled or sock_throttled. And same for the
constant name.

Otherwise,
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>

Thanks!