From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <aliguori@us.ibm.com>
Subject: Re: [PATCH] Convert shutdown to use xenstore
Date: Thu, 04 Aug 2005 21:18:51 -0500
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To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dan Smith <danms@us.ibm.com>, xen-devel@lists.xensource.com
List-Id: xen-devel@lists.xenproject.org

Rusty Russell wrote:

>/* Only required if your code runs in dom0 as well as domU */
>static int register_xenstore_notifier(struct notifier_block *notifier)
>{
>	int ret = 0;
>
>	down(&xenbus_lock);
>	if (xen_start_info.evtchn)
>		ret = notifier.notifier_call(notifier, 0, NULL);
>	else
>		notifier_chain_register(&xenstore_chain, nb);
>	up(&xenbus_lock);
>	return ret;
>}
>  
>
I like this.  It avoids having special case code for dom0 in all the 
drivers.

>Implementation detail: just use the xenbus_lock rather than another
>lock, and make sure you hold it while traversing, not just registering!
>  
>
I was following kernel/cpu.c:cpu_down().  Definitely makes sense though.

Regards,

Anthony Liguori

>Rusty.
>  
>