From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Andres Lagar-Cavilla" <andres@lagarcavilla.org>
Subject: Re: [PATCH 3 of 7] Rework locking in the PoD layer
Date: Thu, 9 Feb 2012 06:45:48 -0800
Message-ID: <ff07926d9c888f8e55bfff494d8ef2ac.squirrel@webmail.lagarcavilla.org>
References: <patchbomb.1328766345@xdev.gridcentric.ca>
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To: George Dunlap <George.Dunlap@eu.citrix.com>
Cc: andres@gridcentric.ca, xen-devel@lists.xensource.com, tim@xen.org, keir.xen@gmail.com, adin@gridcentric.ca
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> 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
>> =A0 =A0 =A0 =A0 unmap_domain_page(b);
>> =A0 =A0 }
>>
>> + =A0 =A0/* First, take all pages off the domain list */
>> =A0 =A0 lock_page_alloc(p2m);
>> -
>> - =A0 =A0/* First, take all pages off the domain list */
>> =A0 =A0 for(i=3D0; i < 1 << order ; i++)
>> =A0 =A0 {
>> =A0 =A0 =A0 =A0 p =3D page + i;
>> =A0 =A0 =A0 =A0 page_list_del(p, &d->page_list);
>> =A0 =A0 }
>>
>> + =A0 =A0/* Ensure that the PoD cache has never been emptied.
>> + =A0 =A0 * This may cause "zombie domains" since the page will never be
>> freed. */
>> + =A0 =A0BUG_ON( d->arch.relmem !=3D RELMEM_not_started );
>> +
>> + =A0 =A0unlock_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
>