From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH 12/17] xenpaging: handle HVMCOPY_gfn_paged_out in copy_from/to_user Date: Wed, 15 Dec 2010 14:08:32 +0000 Message-ID: References: <20101215135140.GA4236@aepfle.de> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20101215135140.GA4236@aepfle.de> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Olaf Hering Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 15/12/2010 13:51, "Olaf Hering" wrote: >> I think the condition you wait on should be for a response to your paging >> request. A wake_up() alone is not really sufficient; you need some kind of >> explicit flagging to the vcpu too. Could the paging daemon stick a response >> in a shared ring, or otherwise explicitly flag to this vcpu that it's >> request has been fully satisfied and it's time to wake up and retry its >> operation? Well, really that's a rhetorical question, because that is >> exactly what you need to implement for this waitqueue strategy to work >> properly! > > Yes, there needs to be some reliable event which the vcpu has to pick up. > I will return to work on this issue, but most likely not this year anymore. This is all bugfix stuff which can be slipped into 4.1 during feature freeze. Also, what doesn't get done in time for 4.1.0 can go into 4.1.1 instead, which will likely be 6-8 weeks later. -- Keir