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

Guillaume Thouvenin
2005-03-29T08:14:02Z

On Mon, 2005-03-28 at 13:42 -0800, Paul Jackson wrote:
> Guillaume wrote:
> > The lmbench shows that the overhead (the construction and the sending
> > of the message) in the fork() routine is around 7%.
>
> Thanks for including the numbers. The 7% seems a bit costly, for a bit
> more accounting information. Perhaps dean's suggestion, to not use
> ascii, will help. I hope so, though I doubt it will make a huge
> difference. Was this 7% loss with or without a user level program
> consuming the sent messages? I would think that the number of interest
> would include a minimal consumer task.

Yes, dean's suggestion helps. The overhead is now around 4%

fork_connector disabled:
Process fork+exit: 149.4444 microseconds

fork_connector enabled:
Process fork+exit: 154.9167 microseconds

> Having the "#ifdef CONFIG_FORK_CONNECTOR" chunk of code right in fork.c
> seems unfortunate. Can the real fork_connector() be put elsewhere, and
> the ifdef put in a header file that makes it a no-op if not configured,
> or simply a function declaration, if configured?

I think that it can be moved in include/linux/connector.h

Guillaume