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 v3 3/3] igmp: convert RTNL lock to a spinlock
Date: Wed, 05 Jun 2013 19:40:00 -0700 [thread overview]
Message-ID: <1370486400.24311.316.camel@edumazet-glaptop> (raw)
In-Reply-To: <1370485211-11498-3-git-send-email-amwang@redhat.com>
On Thu, 2013-06-06 at 10:20 +0800, Cong Wang wrote:
> From: Cong Wang <amwang@redhat.com>
>
> It is not necessary to hold RTNL lock to protect mc_list,
> at least IPv6 mcast is using a local spinlock, IPv4 can do
> this too. This patch converts RTNL lock+RCU to spinlock+RCU.
>
Why are you doing this ?
Really, holding a spinlock in this code instead of a mutex brings all
kind of problems.
For example, you have to use GFP_ATOMIC allocations instead of
GFP_KERNEL
Not counting the race/bug you added in ip_mc_join_group()
next prev parent reply other threads:[~2013-06-06 2:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-06 2:20 [Patch net-next v3 1/3] igmp: fix return value of some functions Cong Wang
2013-06-06 2:20 ` [Patch net-next v3 2/3] ipv6,mcast: " Cong Wang
2013-06-06 2:20 ` [Patch net-next v3 3/3] igmp: convert RTNL lock to a spinlock Cong Wang
2013-06-06 2:40 ` Eric Dumazet [this message]
2013-06-06 2:50 ` Cong Wang
2013-06-06 20:16 ` [Patch net-next v3 1/3] igmp: fix return value of some functions David Stevens
2013-06-08 10:56 ` Cong Wang
2013-06-09 2:12 ` David Stevens
2013-06-10 3:07 ` Cong Wang
2013-06-10 3:09 ` Cong Wang
2013-06-10 13:00 ` David Stevens
2013-06-13 8:44 ` Cong Wang
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