Date: Sat, 16 Mar 1996 12:39:53 -0700 (MST) From: Terry Lambert <terry@lambert.org> To: davidg@Root.COM Cc: jkh@time.cdrom.com, dawes@rf900.physics.usyd.edu.au, sos@FreeBSD.org, dyson@FreeBSD.org, current@FreeBSD.org, mmead@Glock.COM Subject: Re: Try this vm_mmap.c -- please Message-ID: <199603161939.MAA17753@phaeton.artisoft.com> In-Reply-To: <199603161406.GAA07890@Root.COM> from "David Greenman" at Mar 16, 96 06:06:26 am
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> >Which turns MAP_PRIVATE *off* for device objects. My Xaccel 1.2 now > >works perfectly! Yay! > > Yes, as John and I have discussed, it really doesn't make any sense to > allow COW (MAP_PRIVATE) mappings of devices. I think forcing them shared > is reasonable. Say I mmap'ed a video card, but I wanted to virtualize the card for multiple console instances. Wouldn't I want COW for that? I'm not saying that it isn't right to disallow non-shared mappings of devices, only that we should try to think of instances of devices where it might be a mistake. And maybe add a flag on the device driver as to what mappings are allowable, assuming there's an example of needing MAP_PRIVATE. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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