Re: [PATCH net-next v5 4/4] net: add per-netns sysctl for devmem autorelease

From: Bobby Eshleman

Date: Tue Oct 28 2025 - 17:14:44 EST


On Mon, Oct 27, 2025 at 06:22:16PM -0700, Mina Almasry wrote:
> On Thu, Oct 23, 2025 at 2:00 PM Bobby Eshleman <bobbyeshleman@xxxxxxxxx> wrote:

[...]

> > diff --git a/net/core/devmem.c b/net/core/devmem.c
> > index 8f3199fe0f7b..9cd6d93676f9 100644
> > --- a/net/core/devmem.c
> > +++ b/net/core/devmem.c
> > @@ -331,7 +331,7 @@ net_devmem_bind_dmabuf(struct net_device *dev,
> > goto err_free_chunks;
> >
> > list_add(&binding->list, &priv->bindings);
> > - binding->autorelease = true;
> > + binding->autorelease = dev_net(dev)->core.sysctl_devmem_autorelease;
> >
>
> Do you need to READ_ONCE this and WRITE_ONCE the write site? Or is
> that silly for a u8? Maybe better be safe.

Probably worth it to be safe.
>
> Could we not make this an optional netlink argument? I thought that
> was a bit nicer than a sysctl.
>
> Needs a doc update.
>
>
> -- Thanks, Mina

Sounds good, I'll change to nl for the next rev. Thanks for the review!

Best,
Bobby