From: Jakub Kicinski <kuba@kernel.org>
To: Fernando Fernandez Mancera <fmancera@suse.de>
Cc: Maoyi Xie <maoyixie.tju@gmail.com>,
"David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
Jan Vaclav <jvaclav@redhat.com>, Andrew Lunn <andrew@lunn.ch>,
Taehee Yoo <ap420073@gmail.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
Subject: Re: [PATCH net] hsr: broadcast netlink notifications in the device's net namespace
Date: Wed, 27 May 2026 16:18:49 -0700 [thread overview]
Message-ID: <20260527161849.738b7f1f@kernel.org> (raw)
In-Reply-To: <21df0b14-f530-4e9a-931a-21154ec18c78@suse.de>
On Wed, 27 May 2026 13:11:57 +0200 Fernando Fernandez Mancera wrote:
> > genlmsg_end(skb, msg_head);
> > - genlmsg_multicast(&hsr_genl_family, skb, 0, 0, GFP_ATOMIC);
> > + genlmsg_multicast_netns(&hsr_genl_family, dev_net(master->dev),
> > + skb, 0, 0, GFP_ATOMIC);
> > + rcu_read_unlock();
> >
>
> The patch makes sense to me. Anyway, I think we can reduce the RCU
> critical section here.
>
> What about moving rcu_read_unlock() after the if and extract the net
> before unlocking? The benefit is minimal but I think it is worth it.
Not sure TBH, we'd need to take a ref on the netns and allocate
a tracker (on DEBUG kernels). One could go either way.
I'm replying because I wanted to question whether this is Fixes+stable@
worthy. Sending the notifications to the namespace where the device is
makes sense. But it's as much a behavior changes as it is a fix.
The commit in question was merged to 5.6, real users clearly don't care.
prev parent reply other threads:[~2026-05-27 23:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAHPEe=GO=2qqWZPwBB4rrXc3mkD0dznp2K78nCsKwF=c-QwxEw@mail.gmail.com>
2026-05-27 7:59 ` [PATCH net] hsr: broadcast netlink notifications in the device's net namespace Maoyi Xie
2026-05-27 11:11 ` Fernando Fernandez Mancera
2026-05-27 23:18 ` Jakub Kicinski [this message]
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