From: Eric Dumazet <eric.dumazet@gmail.com>
To: Cong Wang <amwang@redhat.com>
Cc: netdev@vger.kernel.org,
Stephen Hemminger <stephen@networkplumber.org>,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [Patch net-next v5 3/3] igmp: convert RTNL lock to a spinlock
Date: Sat, 15 Jun 2013 01:26:08 -0700 [thread overview]
Message-ID: <1371284768.3252.151.camel@edumazet-glaptop> (raw)
In-Reply-To: <1371283942.23997.8.camel@cr0>
On Sat, 2013-06-15 at 16:12 +0800, Cong Wang wrote:
> I _did_ try to replace spinlock with mutex, but apparently mutex_lock()
> can't be called with rcu_read_lock() held, which is the case in
> ip_mc_drop_socket().
>
If you hold a mutex, there is no need for rcu_read_lock() at all.
Nobody can change the lists while you are the owner.
We already have nice helpers, lockdep enabled.
check rtnl_dereference() uses
next prev parent reply other threads:[~2013-06-15 8:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-15 7:41 [Patch net-next v5 1/3] igmp: make some functions void Cong Wang
2013-06-15 7:41 ` [Patch net-next v5 2/3] ipv6,mcast: " Cong Wang
2013-06-15 7:41 ` [Patch net-next v5 3/3] igmp: convert RTNL lock to a spinlock Cong Wang
2013-06-15 7:55 ` Eric Dumazet
2013-06-15 8:12 ` Cong Wang
2013-06-15 8:26 ` Eric Dumazet [this message]
2013-06-15 8:44 ` Cong Wang
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