Messages in this thread |  | | Date | Tue, 4 Jun 1996 20:28:25 +0100 (BST) | From | Darren J Moffat <> | Subject | Re: SVGA kernel chipset drivers. |
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First please note I'm not relpying to anyones message in particular, I've just got a few things that I think need to be said.
I can see several reasons for people wanting to "enhance" the kernel/graphics card "cooperation":
1. Security, setuid is a big problem just to do graphics
2. Speed, lots calls to ioperm()/iopl() can't be good for performance
3. Tidyness, Some might say it makes more sense for the kernel to do for graphics what it does for sound.
4. Quicker uptime with new graphics cards in userlevel if we can assume some basic interface. (JoeWhizo new graphics card can run, but not at it's best X on last years kernel even when we don't have any specs for it yet.)
My comments on these "reasons":
1. This problem is already solved -> POSIX.6, the process (XF86_*, or SVGAlib) gets the single priv to use ioperm/iopl and can't do anyother things a setuid0 binary can.
(For those that don't know, I'm currently working on the POSIX.6 implementation and should have something useable for a more general beta for putting into 2.1.x)
2. I can only see a help here if the speed problem is the user<->kernel jumpping around.
3. Sometimes a good idea - look at VFS and the Soundcard stuff nice and tidy they could all be a terible hack and random interfaces from userlevel libs to kernel.
4. This can be important and very helpfull, eg I've found very few videocards that don't work in Windoze bog standard VGA mode. It would be nice if Linux could have this sort of basic expectation as well, graphical install programs for first time users wither they be X/SVGA or other.
Just for the record I'm writting this in a 80x50 textmode with a thin font, but yesterday I was running X - why? variety is the spice of life!
I'm willing to try kernel level graphics stuff if it gets me better performance/security/stability - or even just one providing it doesn't compromise the others.
I don't think SVGAlib as it stands is cutting is, and I really don't care how many XServers there are - I've got 3 different Xservers on my Sun at work and only one XF86 server at home, disk space bloat isn't an issue - you only install the one you really need and if the SVGA one is a bloat that causes you concern then you need a better install program that relinks with only the card you have in your machine (but as I understand life in Linux this don't really matter much anyway because of demandloading and friends).
Whew.. there I've said what I had to say do with it what you wish.
-- Darren J Moffat
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