Re: [PATCH 3 of 7] Rework locking in the PoD layer

["Andres Lagar-Cavilla" <andres@lagarcavilla.org>]

> On Thu, Feb 9, 2012 at 5:45 AM, Andres Lagar-Cavilla
> <andres@lagarcavilla.org> wrote:
>> @@ -114,15 +114,20 @@ p2m_pod_cache_add(struct p2m_domain *p2m
>>         unmap_domain_page(b);
>>     }
>>
>> +    /* First, take all pages off the domain list */
>>     lock_page_alloc(p2m);
>> -
>> -    /* First, take all pages off the domain list */
>>     for(i=0; i < 1 << order ; i++)
>>     {
>>         p = page + i;
>>         page_list_del(p, &d->page_list);
>>     }
>>
>> +    /* Ensure that the PoD cache has never been emptied.
>> +     * This may cause "zombie domains" since the page will never be
>> freed. */
>> +    BUG_ON( d->arch.relmem != RELMEM_not_started );
>> +
>> +    unlock_page_alloc(p2m);
>> +
>
> I thought we were going to get rid of this BUG_ON? :-)
>
> Other than that, assuming that you've tested it and it works:

Well, I've tested it for months. Does it work? Can that ever be fully
answered? ;)

>
> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>

Great, thanks George!

Tim, I can resend with BUG_ON eliminated and George's Acked-by. Or, wait
for more comments. Or, send a micro-patch later removing the BUG_ON.

Andres
>