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References: <20250117102612.132644-1-atenart@kernel.org> <20250117102612.132644-4-atenart@kernel.org> <20250120114400.55fffeda@kernel.org> <173745203452.4844.5509848806009835293@kwain> <20250121090955.25610044@kernel.org>
Subject: Re: [PATCH net-next 3/4] net-sysfs: prevent uncleared queues from being re-added
From: Antoine Tenart <atenart@kernel.org>
Cc: davem@davemloft.net, pabeni@redhat.com, edumazet@google.com, stephen@networkplumber.org, gregkh@linuxfoundation.org, netdev@vger.kernel.org
To: Jakub Kicinski <kuba@kernel.org>
Date: Wed, 22 Jan 2025 09:34:34 +0100
Message-ID: <173753487461.42919.835203071839984908@kwain>

Quoting Jakub Kicinski (2025-01-21 18:09:55)
> On Tue, 21 Jan 2025 10:33:54 +0100 Antoine Tenart wrote:
> > Quoting Jakub Kicinski (2025-01-20 20:44:00)
> > > On Fri, 17 Jan 2025 11:26:10 +0100 Antoine Tenart wrote: =20
> > > > +     if (unlikely(kobj->state_initialized))
> > > > +             return -EAGAIN; =20
> > >=20
> > > we could do some weird stuff here like try to ignore the sysfs=20
> > > objects and "resynchronize" them before releasing rtnl.
> > > Way to hacky to do now, but also debugging a transient EAGAIN
> > > will be a major PITA. How about we add a netdev_warn_once()
> > > here to leave a trace of what happened in the logs? =20
> >=20
> > I'm not sure as the above can happen in normal conditions, although
> > removing and re-adding queues very shortly might be questionable? On the
> > other hand I get your point and that might not happen very frequently
> > under normal conditions and that's just because I'm hammering the thing
> > for testing.
> >=20
> > It feel a bit weird to warn something that is not unexpected behavior,
> > but if you still prefer having a warn_once for better UX I can add it,
> > let me know.
>=20
> IMHO it's worth adding, but I also don't feel very strongly about it :S=20

Let's add it then; we can always remove it later if needed, especially
as the series will live in net-next for some time.

Thanks!
Antoine