2004-06-07 20:48:36

by Sharma Sushant

Subject: when is alloc_skb called

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

2004-06-07 23:44:47

by Ben Collins

Subject: Re: when is alloc_skb called

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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2004-06-27 04:10:16

by Arnaldo Carvalho de Melo

Subject: Re: when is alloc_skb called

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