unregister_xenbus_watch() handling of xenwatch_mutex

unregister_xenbus_watch() handling of xenwatch_mutex

[Jan Beulich]

2.6.23 acquires the mutex before canceling pending events, whereas
linux-2.6.18-xen acquires and releases the mutex back-to-back after
doing the cancellation. It would seem to me that the former method is
more robust, but otoh I'm wondering why this change then wasn't also
made in the 2.6.18 tree.

Thanks, Jan

Re: unregister_xenbus_watch() handling of xenwatch_mutex

[Keir Fraser]

That's a question for Jeremy. I think the 2.6.18 version is equally correct
and only needs one if statement. Maybe hoisting the lock acquisition gave
Jeremy a warmer fuzzy feeling? :-)

 -- Keir

On 18/10/07 12:38, "Jan Beulich" <jbeulich@novell.com> wrote:

> 2.6.23 acquires the mutex before canceling pending events, whereas
> linux-2.6.18-xen acquires and releases the mutex back-to-back after
> doing the cancellation. It would seem to me that the former method is
> more robust, but otoh I'm wondering why this change then wasn't also
> made in the 2.6.18 tree.
> 
> Thanks, Jan
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: unregister_xenbus_watch() handling of xenwatch_mutex

[Jeremy Fitzhardinge]

Keir Fraser wrote:
> That's a question for Jeremy. I think the 2.6.18 version is equally correct
> and only needs one if statement. Maybe hoisting the lock acquisition gave
> Jeremy a warmer fuzzy feeling? :-)
>   

I don't remember changing this specifically.  It might have been in
response to a review comment, or maybe xen-unstable changed since I
grabbed the code...

    J