Re: [Elsa-devel] Re: [PATCH 2.6.11-rc3-mm2] connector: Add a fork connector

[Evgeniy Polyakov <johnpol@2ka.mipt.ru>]

[-- Attachment #1: Type: text/plain, Size: 1982 bytes --]

On Mon, 2005-02-21 at 09:05 +0100, Guillaume Thouvenin wrote:
> On Thu, 2005-02-17 at 18:50 +0300, Evgeniy Polyakov wrote:
> > >  
> > > +#if defined(CONFIG_CONNECTOR) && defined(CONFIG_FORK_CONNECTOR)
> > 
> > I suspect CONFIG_FORK_CONNECTOR is enough.
> 
> The problem here is that if connector is compiled as a module and
> fork_connector as builtin there will be undefined reference to symbol
> like 'cn_already_initialized' or 'cn_netlink_send'. That's why the
> fork_connector() must be enable if CONFIG_CONNECTOR and
> CONFIG_FORK_CONNECTOR are selected as builtin and not as a module. I
> agree that it's not very elegant...

Maybe "depends on CONNECTOR=y" ?

> > > +			cn_netlink_send(msg, 1);
> > 
> > "1" here means that this message will be delivered to any group
> > which has it's first bit set(1, 3, and so on) in given socket queue.
> > I suspect it is not what you want.
> > By design connector's users should send messages to the group it was
> > registered with
> > (which is obtained from idx field of the struct cb_id), in your case it
> > is CN_IDX_FORK,
> > and connector userspace consumers should bind to the same group (idx
> > value).
> > It is of course not requirement, but a fair path(hmm, I can add more
> > strict checks into connector).
> > By setting 0 as second parameter for cn_netlink_send() you will force
> > connector's core
> > to select proper group for you.
> 
> Yes but cn_netlink_send() is looking for a callback with the same idx.
> As I don't use any callback, found == 0 and I have an error "Failed to
> find multicast netlink group for callback[0xfeed.0xbeef]". So the good
> call is: cn_netlink_send(msg, CN_IDX_FORK);

Uh-oh, I see...
I recall your previous patch with the fork_callback()...

Nevertheless "1" is a bad idea, CN_IDX_FORK is what is expected.

> Thanks for your help,
> Guillaume
-- 
        Evgeniy Polyakov

Crash is better than data corruption -- Arthur Grabowski

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]