From: David Miller <davem@davemloft.net>
To: fleitner@redhat.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] niu: fix SMP race protecting rx_rings and tx_rings
Date: Thu, 03 Feb 2011 15:53:13 -0800 (PST) [thread overview]
Message-ID: <20110203.155313.115940720.davem@davemloft.net> (raw)
In-Reply-To: <20110203234748.GB3710@redhat.com>
From: Flavio Leitner <fleitner@redhat.com>
Date: Thu, 3 Feb 2011 21:47:48 -0200
> On Thu, Feb 03, 2011 at 03:22:14PM -0800, David Miller wrote:
>> One thing I'm worried about with your patch is that the statistics
>> method can be called in basically any context, therefore a sleeping
>> lock like the rw_semaphore is probably not usable.
>>
>> In fact I'm going to revert your patch for now because of this issue.
>
> Oops, I didn't see it there. I thought all calls there were process
> context. Anyway, RCU then...
Yes, one example is the dev_get_stats() call made in
drivers/net/bonding/bond_main.c, which occurs with a
rw spinlock held and BH disabled.
> thanks for reviewing it,
No problem. I think I even have a way to fix this without using RCU
(directly). Just some memory barriers during allocation of the
channels.
I'll post the patch after I'm done with it, thanks again Falvio.
prev parent reply other threads:[~2011-02-03 23:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-03 18:45 [PATCH] niu: fix SMP race protecting rx_rings and tx_rings Flavio Leitner
2011-02-03 22:21 ` David Miller
2011-02-03 23:18 ` Flavio Leitner
2011-02-03 23:22 ` David Miller
2011-02-03 23:47 ` Flavio Leitner
2011-02-03 23:53 ` David Miller [this message]
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