From: Aaron Conole <aconole@redhat.com>
To: "Toke Høiland-Jørgensen" <toke@redhat.com>
Cc: Eelco Chaudron <echaudro@redhat.com>,
Ilya Maximets <i.maximets@ovn.org>,
Alexei Starovoitov <ast@kernel.org>,
Jesse Gross <jesse@nicira.com>,
Adrian Moreno <amorenoz@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>,
netdev@vger.kernel.org, dev@openvswitch.org
Subject: Re: [PATCH v2] net: openvswitch: Avoid needlessly taking the RTNL on vport destroy
Date: Mon, 15 Dec 2025 08:14:07 -0500 [thread overview]
Message-ID: <f7t5xa7anvk.fsf@redhat.com> (raw)
In-Reply-To: <20251211115006.228876-1-toke@redhat.com> ("Toke Høiland-Jørgensen"'s message of "Thu, 11 Dec 2025 12:50:05 +0100")
Toke Høiland-Jørgensen <toke@redhat.com> writes:
> The openvswitch teardown code will immediately call
> ovs_netdev_detach_dev() in response to a NETDEV_UNREGISTER notification.
> It will then start the dp_notify_work workqueue, which will later end up
> calling the vport destroy() callback. This callback takes the RTNL to do
> another ovs_netdev_detach_port(), which in this case is unnecessary.
> This causes extra pressure on the RTNL, in some cases leading to
> "unregister_netdevice: waiting for XX to become free" warnings on
> teardown.
>
> We can straight-forwardly avoid the extra RTNL lock acquisition by
> checking the device flags before taking the lock, and skip the locking
> altogether if the IFF_OVS_DATAPATH flag has already been unset.
>
> Fixes: b07c26511e94 ("openvswitch: fix vport-netdev unregister")
> Tested-by: Adrian Moreno <amorenoz@redhat.com>
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> ---
LGTM,
Acked-by: Aaron Conole <aconole@redhat.com>
next prev parent reply other threads:[~2025-12-15 13:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-11 11:50 [PATCH v2] net: openvswitch: Avoid needlessly taking the RTNL on vport destroy Toke Høiland-Jørgensen
2025-12-15 8:41 ` Eelco Chaudron
2025-12-15 11:58 ` Toke Høiland-Jørgensen
2025-12-15 12:31 ` Eelco Chaudron
2025-12-22 11:29 ` Paolo Abeni
2025-12-22 11:44 ` Eelco Chaudron
2025-12-15 13:14 ` Aaron Conole [this message]
[not found] ` <CAKDHXDHsdfRfaDyfzoTymsPkm=mPdFtJOA=GHb6HGx6TjvYA7w@mail.gmail.com>
2025-12-16 11:59 ` Adrián Moreno
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