Subject: Re: skbuff truesize incorrect.

From: Jim Baxter <[email-masked]>
Date: Fri, 23 May 2014 12:13:23 +0100

On 23/05/14 11:45, David Laight wrote:
> From: Bjørn Mork [mailto:[email-masked]]
>> David Laight <[email-masked]> writes:
> ...
>>> Note that some of the usb ethernet drivers allocate large skb then
>>> lie about the truesize.
>>
>> Hmm, which drivers are these?
> 
> $ grep truesize linux/drivers/net/usb/*
> 
> asix_88179_178a, smsc95xx, sr9700.
> 
> 	David
> 

What are the side effects of changing the truesize, if the original
uncloned skb has the full truesize then isn't the potential memory usage
still counted for the avoidance of OOM?

I suppose if the uncloned skb is deleted you would then have a problem
so a chain of URB's would be the safest solution.

Jim