Re: [PATCH] (1/8) Eliminate brlock in psnap

Zwane Mwaikambo (zwane@holomorphy.com)
Wed, 12 Mar 2003 19:54:28 -0500 (EST)


On Wed, 12 Mar 2003, Paul McKenney wrote:

> You are saying that we can omit locking because this is
> called only from a module-exit function, and thus protected
> by the module_mutex semaphore? (I must defer to
> others who have a better handle on modules...)
>
> If in fact only one module-exit function can be
> executing at a given time, then we should be able to
> use the following approach:

Yes the ->exit call is protected by module_mutex globally.

> Module unloading should be rare enough to tolerate
> the grace period under the module_mutex, right?
>
> Thoughts?

I would agree. However can't unregister_snap_client be used in other paths
apart from module_unload? I wouldn't worry too much since if
register_snap_client and unregister_snap_client for the same protocol
races it's a bug in the caller's code. The safe RCU list removal and
synchronize_kernel should protect us from sane usage.

Zwane
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/