From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: map memory holes with same page Date: Mon, 23 May 2011 13:03:34 +0200 Message-ID: <20110523110334.GA21810@aepfle.de> References: <291EDFCB1E9E224A99088639C4762022B37FC17D49@LONPMAILBOX01.citrite.net> <20110523091307.GC12250@whitby.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20110523091307.GC12250@whitby.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Tim Deegan Cc: Keir Fraser , Paul Durrant , "xen-devel@lists.xensource.com" , James Harper List-Id: xen-devel@lists.xenproject.org On Mon, May 23, Tim Deegan wrote: > At 09:42 +0100 on 23 May (1306143771), Paul Durrant wrote: > > > -----Original Message----- > > [snip] > > > > > > Should there be a performance impact if Windows tries to touch a > > > page that I have previously given pack with decrease_reservation? > > > Will that invoke the PoD sweep? > > > > > > > No. The p2m entry will be 'invalid', not 'PoD'. IIRC the sweep should > > only be invoked if the cache is exhausted when trying to fix up a PoD > > entry. > > But yes, there will be a performance impact because all accesses to the > missing page will be emulated by sending an ioreq to qemu, so it will > run _very_ slowly. Isnt that what I just "fixed" for kdump, the new get_mem_type hvmop? Could that be reused for this Windows issue? Olaf