Re: [PATCH net-next v2 4/5] vxlan: vnifilter: account the VNI node to memcg

[netdev-bot+sashiko@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue(s) to consider:

Critical: 0 · High: 0 · Medium: 0 · Low: 1

- [Low] Missing Fixes: tag — the concern asserts that because the patch
  corrects observable memory-controller behavior for a long-lived per-…

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vxlan: vnifilter: account the VNI node to memcg

This switches the struct vxlan_vni_node allocation in vxlan_vni_alloc()
from plain GFP_KERNEL to GFP_KERNEL_ACCOUNT, so the per-VNI node is
charged to the caller's cgroup like the per-CPU stats block that follows
it.

Link: https://lore.kernel.org/netdev/20260909092645.3105263-1-alishmery18@gmail.com/

> diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
> index 9a1baca39d8b0..fbff52c450c07 100644
> --- a/drivers/net/vxlan/vxlan_vnifilter.c
> +++ b/drivers/net/vxlan/vxlan_vnifilter.c
> @@ -710,7 +710,7 @@ static struct vxlan_vni_node *vxlan_vni_alloc(struct vxlan_dev *vxlan,
>  {
>  	struct vxlan_vni_node *vninode;
>  
> -	vninode = kzalloc_obj(*vninode);
> +	vninode = kzalloc_obj(*vninode, GFP_KERNEL_ACCOUNT);

[Severity: Low]
This isn't a bug, but one review pass suggested this change in
vxlan_vni_alloc() should carry:

  Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device")

on the grounds that it changes observable memory-controller behaviour for a
long-lived per-VNI allocation.

Is a Fixes tag wanted here?  The comparable precedent, commit c948f51c1654
("memcg: enable accounting for net_device and Tx/Rx queues"), added
GFP_KERNEL_ACCOUNT to the netdev allocations this builds on and carries no
Fixes tag, and the sibling patch accounting the per-CPU netdev stats in this
series does not carry one either.

There is also a behavioural side to it: with GFP_KERNEL_ACCOUNT, VNI
creation that previously succeeded can now return -ENOMEM once the calling
cgroup hits its limit, which may not be desirable to backport to stable.

>  	if (!vninode)
>  		return NULL;
>  	vninode->stats = netdev_alloc_pcpu_stats(struct vxlan_vni_stats_pcpu);

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Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260916193449.2552039-1-alishmery18%40gmail.com