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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Arun Sharma <asharma@fb.com>
Cc: David Miller <davem@davemloft.net>,
	Maximilian Engelhardt <maxi@daemonizer.de>,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	StuStaNet Vorstand <vorstand@stusta.mhn.de>,
	Yann Dupont <Yann.Dupont@univ-nantes.fr>,
	Denys Fedoryshchenko <denys@visp.net.lb>
Subject: Re: Kernel crash after using new Intel NIC (igb)
Date: Fri, 27 May 2011 21:56:59 +0200	[thread overview]
Message-ID: <1306526219.2533.3.camel@edumazet-laptop> (raw)
In-Reply-To: <4DDFE4D6.4010000@fb.com>

Le vendredi 27 mai 2011 à 10:52 -0700, Arun Sharma a écrit :
> On 5/26/11 8:27 PM, Eric Dumazet wrote:
> 
> Looks good. Thanks for taking care of this.
> 
> > +static bool atomic_add_unless_return(atomic_t *ptr, int a, int u, int *newv)
> > +{
> > +	int cur, old = atomic_read(ptr);
> > +
> > +	while (old != u) {
> > +		*newv = old + a;
> > +		cur = atomic_cmpxchg(ptr, old, *newv);
> > +		if (cur == old)
> > +			return true;
> > +		old = cur;
> > +	}
> > +	return false;
> > +}
> 
> This looks very similar to atomic_add_unless(). If we had a
> 
> __atomic_add_unless() that returned "old", we could then do:
> 
> atomic_add_unless() { return __atomic_add_unless() != u }
> atomic_add_unless_return() { return __atomic_add_unless() + a}
> 

Sure !

I preferred to not touch lot of files in kernel (atomic_add_unless() is
defined in several files) because its a stable candidate patch (2.6.36+)

So a cleanup patch for 2.6.40+ is certainly doable, do you want to do
this ?

Thanks

  reply	other threads:[~2011-05-27 19:56 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-24 22:32 Kernel crash after using new Intel NIC (igb) Maximilian Engelhardt
2011-04-26 23:34 ` Wyborny, Carolyn
2011-04-27 11:46   ` Maximilian Engelhardt
2011-04-27 12:04     ` Eric Dumazet
2011-04-27  4:24 ` Eric Dumazet
2011-04-27  4:32   ` Eric Dumazet
2011-04-27 11:51     ` Maximilian Engelhardt
2011-05-12 21:10       ` Arun Sharma
2011-05-12 21:15         ` Eric Dumazet
2011-05-24 21:33           ` Arun Sharma
2011-05-25  2:44             ` Eric Dumazet
2011-05-25  6:06               ` Arun Sharma
2011-05-25  6:35                 ` Eric Dumazet
2011-05-26 15:06                   ` Ben Hutchings
2011-05-26 19:30                   ` Arun Sharma
2011-05-26 19:47                     ` Eric Dumazet
2011-05-26 21:48                       ` Arun Sharma
2011-05-26 22:01                         ` Eric Dumazet
2011-05-27  0:09                           ` Arun Sharma
2011-05-27  3:27                             ` Eric Dumazet
2011-05-27  7:56                               ` Yann Dupont
2011-05-27 17:40                               ` David Miller
2011-05-27 17:52                               ` Arun Sharma
2011-05-27 19:56                                 ` Eric Dumazet [this message]
2011-05-27 21:14                                   ` Arun Sharma
2011-05-28  5:41                                     ` Eric Dumazet
2011-05-28 18:04                                       ` Ingo Molnar
2011-05-29  7:33                                         ` Eric Dumazet
2011-05-29  7:38                                           ` Ingo Molnar
2011-05-29  7:43                                             ` Eric Dumazet
2011-05-29 12:33                                               ` Ingo Molnar
2011-05-30 18:34                                                 ` Arun Sharma
2011-05-31 10:50                                                   ` Ingo Molnar
2011-07-13 13:38                               ` Maximilian Engelhardt

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