Re: [PATCH] Notifier for significant events on i386

John Levon (levon@movementarian.org)
Wed, 11 Dec 2002 20:27:27 +0000


On Wed, Dec 11, 2002 at 05:13:37PM +0530, Vamsi Krishna S . wrote:

> Unless I am missing something, notifiers have always been racy.
> No amount of locking you do in individual modules to prevent
> races will help as the notifier chain is walked inside
> notifier_call_chain() in kernel/sys.c. One would need to
> add some form of locking there (*) so that users of notifier
> chains need not worry about races/locking at all.

There are notifiers being used that sleep inside the called notifiers.

You could easily make a __notifier_call_chain that is lockless and
another one that readlocks the notifier_lock ...

regards
john

-- 
"Anyone who says you can have a lot of widely dispersed people hack away on
 a complicated piece of code and avoid total anarchy has never managed a 
 software project."
	- Andy Tanenbaum
-
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/