From: Christoph Hellwig <hch@lst.de>
To: David Miller <davem@davemloft.net>
Cc: hch@lst.de, netdev@vger.kernel.org
Subject: Re: [PATCH 1/5] net: remove bogus RCU annotations on socket.wq
Date: Mon, 30 Jul 2018 09:44:54 +0200 [thread overview]
Message-ID: <20180730074454.GA10461@lst.de> (raw)
In-Reply-To: <20180729.130551.870321755786430124.davem@davemloft.net>
On Sun, Jul 29, 2018 at 01:05:51PM -0700, David Miller wrote:
> From: Christoph Hellwig <hch@lst.de>
> Date: Fri, 27 Jul 2018 16:02:10 +0200
>
> > We never use RCU protection for it, just a lot of cargo-cult
> > rcu_deference_protects calls.
> >
> > Note that we do keep the kfree_rcu call for it, as the references through
> > struct sock are RCU protected and thus might require a grace period before
> > freeing.
> >
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
>
> These were added by Eric Dumazet and I would never accuse him of cargo
> cult programming.
>
> All of the rcu_dereference_protects() calls are legit, even though some
> of them use '1' as the protects condition because in fact we know the
> object is dead and gone through an RCU cycle at that point.
I disagree, but I'll resend it the patch with Eric and Paul in CC to
settle the argument.
next prev parent reply other threads:[~2018-07-30 9:14 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-27 14:02 socket poll related cleanups Christoph Hellwig
2018-07-27 14:02 ` [PATCH 1/5] net: remove bogus RCU annotations on socket.wq Christoph Hellwig
2018-07-29 20:05 ` David Miller
2018-07-30 7:44 ` Christoph Hellwig [this message]
2018-07-30 16:09 ` David Miller
2018-07-27 14:02 ` [PATCH 2/5] net: simplify sock_poll_wait Christoph Hellwig
2018-07-27 14:02 ` [PATCH 3/5] net: don not detour through struct sock to find the poll waitqueue Christoph Hellwig
2018-07-27 14:02 ` [PATCH 4/5] net: remove sock_poll_busy_loop Christoph Hellwig
2018-07-27 14:02 ` [PATCH 5/5] net: remove sock_poll_busy_flag Christoph Hellwig
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