Re: Tips for module_init() dependencies

From: Gregory Haskins
Date: Thu Oct 15 2009 - 12:00:55 EST


Daniel Walker wrote:
> On Thu, 2009-10-15 at 09:01 -0400, Gregory Haskins wrote:
>
>> may break, because the kernel seems to have no concept of
>> interdependency between foo_init() and bar_init(), and therefore
>> bar_init() may call foo() before foo_init() has executed.
>>
>> There are various ways to solve this problem, such as deferring calling
>> foo() with a workqueue or something, but I was wondering if there was a
>> better/standard way to do this that I am missing?
>>
>> The problem I am having specifically is that I am trying to call
>> configfs_register_subsystem() in a module_init(), but this breaks when
>> built into the kernel based on sheer bad luck that configfs gets
>> initialized after me. To date I have worked around this by forcing my
>> code to only support built-in, and using late_initcall() instead or
>> module_init. This works, but it only means I am putting the problem off
>> (code that depends on *me* has to use similar tricks, etc.
>
> You can't modify the build order so your module get "builtin" after
> configfs?
>

Hi Daniel,

Possibly.

A) Any suggestions on how? Can I express this in Kconfig or something
(i.e. "depends on FOO"). I currently have "select FOO" in the BAR
object, but this doesn't seem to be sufficient to describe the relationship.

B) Do I have to make the entire chain follow suit? (I have C deps on B,
B deps on A kind of scenarios)

Kind Regards,
-Greg


Attachment: signature.asc
Description: OpenPGP digital signature