when is alloc_skb called

when is alloc_skb called

[Sushant Sharma]

Hi All

I want to know which are the evnets
that can lead to the calling of alloc_skb
function which is used to allocate sk_buff.
Arrival and departure of packet are 2 events
which I know. Are there any other events/cases
which can lead to alloc_skb(...) function call in kernel.

Thanks for help
Sushant

Re: when is alloc_skb called

[Ben Collins]

On Mon, Jun 07, 2004 at 03:29:14PM -0600, Sushant Sharma wrote:
> Hi All
> 
> I want to know which are the evnets
> that can lead to the calling of alloc_skb
> function which is used to allocate sk_buff.
> Arrival and departure of packet are 2 events
> which I know. Are there any other events/cases
> which can lead to alloc_skb(...) function call in kernel.

Some non-network related drivers use skb's for non-network related
things (ieee1394 is one such abuser).

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Re: when is alloc_skb called

[Arnaldo Carvalho de Melo]

Ben Collins wrote:
> On Mon, Jun 07, 2004 at 03:29:14PM -0600, Sushant Sharma wrote:
> 
>>Hi All
>>
>>I want to know which are the evnets
>>that can lead to the calling of alloc_skb
>>function which is used to allocate sk_buff.
>>Arrival and departure of packet are 2 events
>>which I know. Are there any other events/cases
>>which can lead to alloc_skb(...) function call in kernel.
> 
> 
> Some non-network related drivers use skb's for non-network related
> things (ieee1394 is one such abuser).
> 

And some network protocol stacks use it to report events, like
connection requests, etc see the x25 code, for instance 
(x25_establish_link, x25_terminate_link), sometimes allocating
1 byte, sometimes using the skb->cb scratch area.

- Arnaldo