Date: Mon, 05 Dec 2011 11:58:28 -0600
From: Alan Cox <alc@rice.edu>
To: Andriy Gapon <avg@FreeBSD.org>
Cc: Gleb Kurtsou <gleb.kurtsou@gmail.com>, Alan Cox <alc@FreeBSD.org>, freebsd-emulation@FreeBSD.org, FreeBSD current <freebsd-current@FreeBSD.org>, Bernhard Froehlich <decke@FreeBSD.org>, Jung-uk Kim <jkim@FreeBSD.org>
Subject: Re: Freeze with 10.0 and VirtualBox {4.1.4|4.1.6|4.1.51r38464}
Message-ID: <4EDD0644.5030902@rice.edu>
In-Reply-To: <4EDCCDA2.5070006@FreeBSD.org>
References: <4ECF7440.4070300@entel.upc.edu> <20111126163343.GA9150@reks> "<4ED6AEFE.4010106@FreeBSD.org>" <201111301807.21351.jkim@FreeBSD.org> <60ea779052f025798cf65e18c24b7b31@bluelife.at> <47eb9f9b139dd8c59b050f1670a5f18d@bluelife.at> <7c3c9505867f4528af276a571077b9ce@bluelife.at> <4EDCC1C6.3040109@FreeBSD.org> <ce531a25e601ca82701d259808d7d485@bluelife.at> <4EDCCDA2.5070006@FreeBSD.org>
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On 12/05/2011 07:56, Andriy Gapon wrote: > on 05/12/2011 15:15 Bernhard Froehlich said the following: >> On 05.12.2011 14:06, Andriy Gapon wrote: >>> on 05/12/2011 14:57 Bernhard Froehlich said the following: >>>> On 02.12.2011 12:55, Bernhard Froehlich wrote: >>>>> Patch has been send upstream: >>>>> >>>>> >>>>> >>>>> https://www.virtualbox.org/pipermail/vbox-dev/2011-December/004842.html >>>> Patches have been committed upstream. Thanks a lot guys! >>>> >>>> https://www.virtualbox.org/changeset/39521 >>>> >>> BTW, I think that we additionally need VM_ALLOC_NOBUSY in flags that >>> we pass to vm_phys_alloc_contig. >> What's the difference of this? > Pages should be marked busy only for some special occasions, wired pages are not > normally busy; the correct explanation is quite a bit longer than this, the > comment in the code explains VPO_BUSY as "page is in transit". Right now this > flag doesn't seem tom affect vboxdrv code but it may lead to surprises when some > parts of code that are incorrect now are re-implemented properly: > http://article.gmane.org/gmane.os.freebsd.devel.emulation/9297 VM_ALLOC_NOOBJ implies that the returned page does not have VPO_BUSY set. From the comment at the head of both vm_page_alloc() and vm_page_alloc_contig(): * VM_ALLOC_NOOBJ page is not associated with an object and * should not have the flag VPO_BUSY set With regard to the message that the above link points to, I suspect that the introduction of vm_page_alloc_contig() can be used to address the first problem that you point out. Specifically, one or more OBJT_PHYS vm objects could be created and passed to vm_map_find() and then vm_page_alloc_contig() could be used to fill these vm objects with memory. Alan
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