From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48D17E75.80807@redhat.com> Date: Wed, 17 Sep 2008 15:02:29 -0700 From: Avi Kivity MIME-Version: 1.0 Subject: Re: Populating multiple ptes at fault time References: <48D142B2.3040607@goop.org> In-Reply-To: <48D142B2.3040607@goop.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Jeremy Fitzhardinge Cc: Nick Piggin , Hugh Dickens , Linux Memory Management List , Linux Kernel Mailing List , Avi Kivity , Andrew Morton , Rik van Riel List-ID: Jeremy Fitzhardinge wrote: > Minor faults are easier; if the page already exists in memory, we should > just create mappings to it. If neighbouring pages are also already > present, then we can can cheaply create mappings for them too. > > One problem is the accessed bit. If it's unset, the shadow code cannot make the pte present (since it has to trap in order to set the accessed bit); if it's set, we're lying to the vm. This doesn't affect Xen, only kvm. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org