network driver that uses skb destructor

From: Sirotkin, Alexander (demiurg_at_ti.com)
Date: 12/29/03

  • Next message: Michael Guntsche: "Network problems with b44 in 2.6.0" 
    To: linux-kernel@vger.kernel.org
Date:	Mon, 29 Dec 2003 18:53:59 +0200

    I would like to write a network driver that uses DMA and manages it's
    own memory.

    The most common approach (in RX) seem to be to allocate the memory for
    DMA transfer using dev_alloc_skb(), get the HW DMA engine to transfer
    the packet into this skb buffer and later free it using dev_kfree_skb().

    For various reasons (mainly to support legacy source code) I would like
    to allocate and free the buffer using my own functions. Theoretically, I
    could get away by using skb->destructor.

    When I receive a packet I could allocate a zero length skb, point
    skb->data to my (already allocated) buffer which contains the packet and
    register the skb->destructor callback. Later, when this skb would be
    freed my destructor callback would be called and it would return the
    buffer to driver's pool.

    It seems to me that it should work, but I'm a little bit cautions
    because I could not find a single network driver (in 2.4 kernel) that
    uses such an approach and I'm not extremely eager to be the first one to
    try.

    Anybody tried to implement similar approach ?
    Any thoughts why this would (or would not) work ?

    Thanks a lot. 

    -- 
Alexander Sirotkin
SW Engineer
Texas Instruments
Broadband Communications Israel (BCIL)
Tel:  +972-9-9706587
________________________________________________________________________
"Those who do not understand Unix are condemned to reinvent it, poorly."
      -- Henry Spencer 
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  • Next message: Michael Guntsche: "Network problems with b44 in 2.6.0"

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