Re: [patch 1/2] fork_connector: add a fork connector

[Paul Jackson <pj@engr.sgi.com>]

Guillaume wrote:
>   The goal of the fork connector is to inform a user space application
> that a fork occurs in the kernel. This information (cpu ID, parent PID
> and child PID) can be used by several user space applications. It's not
> only for accounting. Accounting and fork_connector are two different
> things and thus, fork_connector doesn't do the merge of any kinds of
> data (and it will never do). 

Yes - it is clear that the fork_connector does this - inform user space
of fork information <cpu, parent, child>.  I'm not saying that
fork_connector should merge data; I'm observing that it doesn't, and
that this would seem to serve the needs of accounting poorly.

Out of curiosity, what are these 'several user space applications?'  The
only one I know of is this extension to bsd accounting to include
capturing parent and child pid at fork.  Probably you've mentioned some
other uses of fork_connector before here, but I missed it.

> The relayfs is done, like Evgeniy said, for large amount of
> datas. So I think that it's not suitable for what we want to achieve
> with the fork connector.

I never claimed that relayfs was appropriate for fork_connector.

I'm not trying to tape a rock to Evgeniy's screwdriver.  I'm saying that
accounting looks like a nail to me, so let us see what rocks and hammers
we have in our tool box.

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                  Paul Jackson <pj@engr.sgi.com> 1.650.933.1373, 1.925.600.0401