Re: several packets in a single buffer in Rx

[Emmanuel Grumbach <egrumbach-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

2011/5/16 Michał Mirosław <mirqus-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
> W dniu 16 maja 2011 14:59 użytkownik Emmanuel Grumbach
> <egrumbach-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> napisał:
>> 2011/5/16 Michał Mirosław <mirqus-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
>>> 2011/5/16 Emmanuel Grumbach <egrumbach-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
>>>> I would like to be able to deliver the same page several times to the
>>>> stack without having the stack consume it before the last time I
>>>> deliver it.
>>>> Of course I would like to avoid cloning it.
>>>
>>> Just do get_page() on the page having another packet in it before
>>> passing skb up.
>>>
>>
>> I can see the path:
>> __kfree_skb -> skb_release_all -> skb_release_data -> put_page
>> put_page will free the page iff the _count variable reaches 0. Of course,
>> _count is incremented by get_page.
>>
>> I will give it try.
>>
>> I understand that this will work regardless the order given to
>> alloc_pages right ?
>
> Yes. Remember that if you put a lot of packets in a big-order page
> then the memory will be freed only after all packets are freed.

Sure. Thanks for the help.

>
> Best Regards,
> Michał Mirosław
>
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