From: Maxime Chevallier <maxime.chevallier@bootlin.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: davem@davemloft.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com,
"Andrew Lunn" <andrew@lunn.ch>,
"Eric Dumazet" <edumazet@google.com>,
"Paolo Abeni" <pabeni@redhat.com>,
"Russell King" <linux@armlinux.org.uk>,
linux-arm-kernel@lists.infradead.org,
"Christophe Leroy" <christophe.leroy@csgroup.eu>,
"Herve Codina" <herve.codina@bootlin.com>,
"Florian Fainelli" <f.fainelli@gmail.com>,
"Heiner Kallweit" <hkallweit1@gmail.com>,
"Vladimir Oltean" <vladimir.oltean@nxp.com>,
"Köry Maincent" <kory.maincent@bootlin.com>,
"Jesse Brandeburg" <jesse.brandeburg@intel.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Marek Behún" <kabel@kernel.org>,
"Piergiorgio Beruto" <piergiorgio.beruto@gmail.com>,
"Oleksij Rempel" <o.rempel@pengutronix.de>,
"Nicolò Veronese" <nicveronese@gmail.com>,
"Simon Horman" <horms@kernel.org>
Subject: Re: [PATCH net-next v5 01/13] net: phy: Introduce ethernet link topology representation
Date: Fri, 5 Jan 2024 10:29:18 +0100 [thread overview]
Message-ID: <20240105102918.24398552@device-28.home> (raw)
In-Reply-To: <20240104151242.52fa8cb4@kernel.org>
Hi Jakub,
On Thu, 4 Jan 2024 15:12:42 -0800
Jakub Kicinski <kuba@kernel.org> wrote:
> On Thu, 21 Dec 2023 19:00:34 +0100 Maxime Chevallier wrote:
> > @@ -2441,6 +2442,7 @@ struct net_device {
> > #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
> > struct netprio_map __rcu *priomap;
> > #endif
> > + struct phy_link_topology link_topo;
>
> Perhaps others would disagree but can we make this a pointer instead?
> Only allocate it on demand, when first PHY gets attached?
> Both saves space and netdevice.h will no longer need to know the
> definition of the struct.
>
> Complete noob question but I thought PHYs get attached at ndo_open
> time for drivers, don't they? We shouldn't want to re-ID in that case.
I'll give it a try, it could be doable to try to keep the index for
_some_ PHYs. I had a first try at this in the very first iteration, but
that was lost when converting to xarray for the index management. Since
the phy_device keeps track of its own index, we can try to re-use it,
but I can see it becoming difficult if we destroy the topology when all
PHYs are detached (after ndo_close).
When re-creating the xarray at the next ndo_open, we would need to know
what was the previous next_index, and we can't know that until PHYs are
all re-attached.
For now it would work because in most cases, we only have one PHY
behind the MAC we can guarantee won't go away, but there are devices
out-there with 2 PHYs connected to the same MAC with a MUX in the
middle (that's one thing this series prepares for), and here it would
be more complex to re-allocate the topology while knowing what's the
next unused index. Hope that makes sense :)
To summarize, I don't think we can easily both dynamically
allocate/destroy the topology based only on the presence of at least
one PHY, and try to keep the PHY index the same for non-hot-pluggable
PHYs.
>
> > struct phy_device *phydev;
> > struct sfp_bus *sfp_bus;
> > struct lock_class_key *qdisc_tx_busylock;
>
> > @@ -10872,6 +10873,8 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
> > #ifdef CONFIG_NET_SCHED
> > hash_init(dev->qdisc_hash);
> > #endif
> > + phy_link_topo_init(&dev->link_topo);
> > +
> > dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
> > setup(dev);
> >
>
> I think you're missing a call to xa_destroy() somewhere, no?
Arg you're right... I was under the false assumption that because the
xarray wasn't dynamically allocated, we didn't need to perform any
cleanup, thanks for spotting this.
Maxime
next prev parent reply other threads:[~2024-01-05 8:32 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 18:00 [PATCH net-next v5 00/13] Introduce PHY listing and link_topology tracking Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 01/13] net: phy: Introduce ethernet link topology representation Maxime Chevallier
2024-01-04 23:12 ` Jakub Kicinski
2024-01-05 2:21 ` Andrew Lunn
2024-01-05 9:29 ` Maxime Chevallier [this message]
2024-01-05 15:34 ` Jakub Kicinski
2023-12-21 18:00 ` [PATCH net-next v5 02/13] net: sfp: pass the phy_device when disconnecting an sfp module's PHY Maxime Chevallier
2024-01-03 15:20 ` Russell King (Oracle)
2024-01-03 17:45 ` Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 03/13] net: phy: add helpers to handle sfp phy connect/disconnect Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 04/13] net: sfp: Add helper to return the SFP bus name Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 05/13] net: ethtool: Allow passing a phy index for some commands Maxime Chevallier
2024-01-04 23:15 ` Jakub Kicinski
2024-01-05 9:30 ` Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 06/13] netlink: specs: add phy-index as a header parameter Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 07/13] net: ethtool: Introduce a command to list PHYs on an interface Maxime Chevallier
2024-01-04 23:34 ` Jakub Kicinski
2024-01-05 9:43 ` Maxime Chevallier
2024-01-05 13:17 ` Andrew Lunn
2024-01-24 13:50 ` Maxime Chevallier
2024-01-24 16:54 ` Andrew Lunn
2024-01-25 8:22 ` Maxime Chevallier
2024-01-25 17:10 ` Andrew Lunn
2024-01-05 15:39 ` Jakub Kicinski
2023-12-21 18:00 ` [PATCH net-next v5 08/13] netlink: specs: add ethnl PHY_GET command set Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 09/13] net: ethtool: plca: Target the command to the requested PHY Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 10/13] net: ethtool: pse-pd: " Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 11/13] net: ethtool: cable-test: " Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 12/13] net: ethtool: strset: Allow querying phy stats by index Maxime Chevallier
2023-12-21 18:00 ` [PATCH net-next v5 13/13] Documentation: networking: document phy_link_topology Maxime Chevallier
2024-01-01 18:40 ` [PATCH net-next v5 00/13] Introduce PHY listing and link_topology tracking patchwork-bot+netdevbpf
2024-01-02 11:57 ` Russell King (Oracle)
2024-01-02 18:51 ` Jakub Kicinski
2024-01-03 14:33 ` Maxime Chevallier
2024-01-04 23:47 ` Jakub Kicinski
2024-01-04 23:50 ` Florian Fainelli
2024-01-05 0:56 ` Jakub Kicinski
2024-01-05 9:00 ` Maxime Chevallier
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