Re: Re: A common layer for Accounting packages

On 28 Feb 2005 10:31:33 -0500
jamal [off-list ref] wrote:

On Mon, 2005-02-28 at 09:25, Thomas Graf wrote:

quoted

* jamal [ref] 2005-02-28 09:10

[..]

quoted

quoted

To justify writting the new code, I am assuming someone has actually sat
down and in the minimal stuck their finger in the air
and said "yes, there is definetely wind there".

I did, not for this problem though. The code this idea comes from sends
batched events 

I would bet the benefit you are seeing has to do with batching rather
than such an optimization flag. Different ballgame.
I relooked at their code snippet, they dont even have skbs built nor
even figured out what sock or PID. That work still needs to be done it
seems in cn_netlink_send(). So probably all they need to do is move the
check in cn_netlink_send() instead. This is assuming they are not
scratching their heads with some realted complexities.

I am gonna disapear for a while; hopefully the original posters have
gathered some ideas from what we discussed.

As connector author, I still doubt it worth copying several lines 
from netlink_broadcast() before skb allocation in cn_netlink_send().
Of course it is easy and can be done, but I do not see any profit here.
Atomic allocation is fast, if it succeds,  but there are no groups/socket to send,
skb will be freed, if allocation fails, then group check is useless.

I would prefer Guillaume Thouvenin as fork connector author to test
his current implementation and show that connector's cost is negligible
both with and without userspace listeners.
As far as I remember it is first entry in fork connector's TODO list.

cheers,
jamal

	Evgeniy Polyakov

Only failure makes us experts. -- Theo de Raadt


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