Date: Wed, 03 Jun 1998 11:52:37 -0500 From: "Chris Csanady" <cc@swing.ca.sandia.gov> To: dg@root.com Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: VM Questions Message-ID: <199806031652.LAA08485@swing.ca.sandia.gov> In-Reply-To: Your message of "Tue, 02 Jun 1998 20:35:34 PDT." <199806030335.UAA19842@implode.root.com>
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>>First, I was wondering if it is possible given a physical address, >>to copy data to it from a virtual address. Or is a virtual mapping >>necessary? > > There must be a virtual mapping. > >>The other question is how may I map user pages into the kernel? I've >>looked through vm_map.c, and it seems that support for this is >>lacking. To get around this for now, I am attempting to use almost >>exclusively physical address--although am now sure how it will work >>out. > > vm_map.c isn't really the right place to look. A better place would be >physio/vmapbuf/vunmapbuf in kern_physio.c and vm_machdep.c. Thanks to all that have pointed me in the right direction wrt this type of thing. :) I think I should have enough info now to get things working properly now. I was kind of curious about one thing though--in vm_page.c, there is mention that vm_hold should only be used for temporary wiring. Is it really bad to use it often? I want to have the process wired anyways, so would this even matter? -Chris To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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