From: Jeff D. <jd...@ka...> - 2001-03-09 22:41:16
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ra...@cs... said: > I know UML doesn't support the multiple processors within UML, Not yet anyway... > but > will it run on a SMP host? Sure, that's no problem. (AFIAK, I've never actually done it) Jeff |
From: Jeff D. <jd...@ka...> - 2001-03-10 00:43:35
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> UML crashes pretty often > I can't seem to run a full system reliably. Then why haven't I seen any complaints or stack traces or anything from you? Bugs are kind of hard to fix if I don't know about them. Jeff |
From: Caleb C. <jo...@cr...> - 2001-03-10 01:01:17
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> > UML crashes pretty often > > I can't seem to run a full system reliably. > > Then why haven't I seen any complaints or stack traces or > anything from you? > > Bugs are kind of hard to fix if I don't know about them. Beleive me, I know. It takes time to make a good bug report -- time which I just haven't taken yet. I know how useless bug reports like, "It's broken, what'w wrong?" are. I just assumed that the current state of UML was that it crashed periodically. When it crashes again, I'll see if I can glean any useful information about the crash and send it in. -Caleb |
From: Jeff D. <jd...@ka...> - 2001-03-10 04:20:37
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jo...@cr... said: > I know how useless bug reports like, "It's broken, what'w wrong?" are. They're almost, but not totally useless. If 10 people say "It's broken, what's wrong" and another says "It's broken, here's a stack trace, what's wrong", that tells me that a lot of people are seeing it, and maybe I'd better fix it quickly. > I just assumed that the current state of UML was that it crashed > periodically. Not as far as I'm concerned. I know of a few ways of crashing it, but except for one, they involve doing specific nasty things. Jeff |
From: Jeff D. <jd...@ka...> - 2001-03-11 17:25:38
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lis...@os... said: > Unless Jeff has taken into account the possibility of two or more > threads/processes being active concurrently I would expect it to be > unstable on SMP. That can't happen. UML is a single processor virtual machine at the moment, so it has only one thread runnable on the host at any given time. Jeff |
From: Jeff D. <jd...@ka...> - 2001-03-11 17:26:09
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lis...@os... said: > Doubtless there's much I do not understand, and that with > understanding I'd see some significant benefits. > Mind you, if performance is important, it's still hard to beat real > hardware. It's not performance. When UML supports SMP again, it will have multiple (one per virtual CPU) threads runnable on the host at any given time. This will allow people to do SMP debugging under UML. It will also allow hosting outfits to offer varying levels of CPU usage to their customers. Low-end customers will get a UP virtual machine which can only have one active process on the host. People who pay more can get virtual SMP boxes which can have more processes active on the host. Jeff |
From: Caleb C. <jo...@cr...> - 2001-03-09 23:47:53
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I've done it, and it works. UML crashes pretty often, but I assumed that was normal. How often to people get UML crashes. I can't seem to run a full system reliably. > -----Original Message----- > From: use...@li... > [mailto:use...@li...]On Behalf Of > Jeff Dike > Sent: Friday, March 09, 2001 3:54 PM > To: ra...@cs... > Cc: use...@li... > Subject: Re: [uml-devel] UML running on SMP host?? > > > ra...@cs... said: > > I know UML doesn't support the multiple processors within UML, > > Not yet anyway... > > > but > > will it run on a SMP host? > > Sure, that's no problem. (AFIAK, I've never actually done it) > > Jeff > > > > _______________________________________________ > User-mode-linux-devel mailing list > Use...@li... > http://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel |
From: <lis...@os...> - 2001-03-11 15:02:48
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On Fri, 9 Mar 2001, Caleb Crome wrote: > I've done it, and it works. UML crashes pretty often, but I assumed that > was normal. How often to people get UML crashes. I can't seem to run a > full system reliably. > I don't, but then I've not worked it at all hard yet. Unless Jeff has taken into account the possibility of two or more threads/processes being active concurrently I would expect it to be unstable on SMP. Try it with only one CPU and see how it compares. |
From: <lis...@os...> - 2001-03-11 15:02:40
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On Fri, 9 Mar 2001, Jeff Dike wrote: > ra...@cs... said: > > I know UML doesn't support the multiple processors within UML, > > Not yet anyway... It's not at all obvious to me that actually supporting multiple CPUs would gain anything. It does need to recognise that it's RUNNING on SMP because there may be several uml-kernel threads/processes running concurrently, just as in any other aplication. In that sense it needs to support SMP, but I don't see that despatching two or more CPUs itself would do much. Doubtless there's much I do not understand, and that with understanding I'd see some significant benefits. Mind you, if performance is important, it's still hard to beat real hardware. |