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From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: tony@atomide.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org
Subject: Re: [PATCH] net: Add back alignment for size for __alloc_skb
Date: Thu, 03 Nov 2011 00:14:12 +0100	[thread overview]
Message-ID: <4EB1CEC4.3090909@gmail.com> (raw)
In-Reply-To: <20111102.190955.1902322759075682192.davem@davemloft.net>

On 03/11/2011 00:09, David Miller wrote:

> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Wed, 02 Nov 2011 23:55:11 +0100
> 
>> There is a problem with your kmalloc() or alignments on your architecture.
>>
>> What is the SMP_CACHE_BYTES value ?
> 
> kmalloc() behavior doesn't have anything to do with this bug.
> 
> The issue is calculation of skb->end, which is based upon calculated
> 'size' variable.
> 
> skb->end determines alignment of skb_shared_info, which is where the
> alignment problem is occuring for Tony.
> 


I understood that David, but check the code, and you can see that exact
skb->end depends also on ksize()

So maybe the right fix is to make sure skb->end is properly aligned, say
with SLOB

So a more generic fix is welcomed.

  parent reply	other threads:[~2011-11-02 23:14 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-02 22:43 [PATCH] net: Add back alignment for size for __alloc_skb Tony Lindgren
2011-11-02 22:55 ` Eric Dumazet
2011-11-02 23:09   ` David Miller
2011-11-02 23:13     ` David Miller
2011-11-02 23:14     ` Eric Dumazet [this message]
2011-11-02 23:17       ` David Miller
2011-11-02 23:19         ` Tony Lindgren
2011-11-02 23:20           ` Eric Dumazet
2011-11-02 23:24             ` Tony Lindgren
2011-11-02 23:31               ` Eric Dumazet
2011-11-02 23:40                 ` Tony Lindgren
2011-11-03 22:09                   ` David Miller
2011-11-02 23:22           ` David Miller

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