Date: Fri, 20 Mar 1998 18:27:49 -0500 (EST) From: "John S. Dyson" <toor@dyson.iquest.net> To: jlemon@americantv.com (Jonathan Lemon) Cc: toor@dyson.iquest.net, mike@smith.net.au, perlsta@cs.sunyit.edu, hackers@FreeBSD.ORG Subject: Re: mremap? Message-ID: <199803202327.SAA18360@dyson.iquest.net> In-Reply-To: <19980320165353.04445@right.PCS> from Jonathan Lemon at "Mar 20, 98 04:53:53 pm"
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> On Mar 03, 1998 at 05:38:01PM -0500, John S. Dyson wrote: > > > On Mar 03, 1998 at 03:11:29PM -0500, John S. Dyson wrote: > > > > I was planning on implementing mremap. I am not sure of the api, but > > > > it should be "easy" to implement with our current VM code. Think > > > > of map entries as being the address space "chunks", and objects as being > > > > the data repositorys. I want to foster others knowing how the code > > > > works, so now I don't want to do it :-). It would take me about 4Hrs > > > > to implement, and I want more people on the project to be able to > > > > do this stuff. The initial learning curve is long, but after that, > > > > there will be more people yet who know how the VM code works!!! :-). > > > > > > I have something similar to this, but slightly different: > > > > > > I want to be able to map part of an address space of one process > > > into the address space of a different process, at a different location, > > > resulting in shared memory between the processes. > > > > > > (Why? I wanted a "vm86" process, with 1MB mapped starting at address 0, > > > and the same region mapped into the "control" process, at a different > > > location.) > > > > > > EG: > > > boolean_t > > > vm_map_shared(smap, dmap, saddr, daddr, size) > > > vm_map_t smap, dmap; > > > vm_offset_t saddr, daddr; > > > vm_size_t size; > > > > > > Would this type of routine be useful? > > > > > I suspect that it would be useful, given a "use." I don't know enough > > about exactly what the userland API would/should look like (re: security, > > and features) to implement it "off the top of my head." > > Oh, I've already have this running, and it's just for internal kernel > use at the moment (no userspace API). What I was really asking was if > this might be useful to a wider audience, and if the semantics aren't > too seriously deranged. > It looks okay, I wouldn't mind if it was added :-). I would support adding it. There is absolutely no reason for me to stand in the way of progress!!! John To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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