Messages in this thread | | | Date | Wed, 03 Sep 2003 19:31:13 -0700 | From | "Martin J. Bligh" <> | Subject | Re: Scaling noise |
| |
> On Wed, Sep 03, 2003 at 06:06:53PM -0700, Larry McVoy wrote: >> Here's a thought. Maybe the next kernel summit needs to have a CC cluster >> BOF or whatever. I'd be happy to show up, describe what it is that I see >> and have you all try and poke holes in it. If the net result was that you >> walked away with the same picture in your head that I have that would be >> cool. Heck, I'll sponser it and buy beer and food if you like. > > It'd be nice if there were a prototype or something around to at least > get a feel for whether it's worthwhile and how it behaves. > > Most of the individual mechanisms have other uses ranging from playing > the good citizen under a hypervisor to just plain old filesharing, so > it should be vaguely possible to get a couple kernels talking and > farting around without much more than 1-2 P-Y's for bootstrapping bits > and some unspecified amount of pain for missing pieces of the above. > > Unfortunately, this means > (a) the box needs a hypervisor (or equivalent in native nomenclature) > (b) substantial outlay of kernel hacking time (who's doing this?) > > I'm vaguely attached to the idea of there being _something_ to assess, > otherwise it's difficult to ground the discussions in evidence, though > worse comes to worse, we can break down to plotting and scheming again.
I don't think the initial development baby-steps are *too* bad, and don't even have to be done on a NUMA box - a pair of PCs connected by 100baseT would work. Personally, I think the first step is to do task migration - migrate a process without it realising from one linux instance to another. Start without the more complex bits like shared filehandles, etc. Something that just writes 1,2,3,4 to a file. It could even just use shared root NFS, I think that works already.
Basically swap it out on one node, and in on another, though obviously there's more state to take across than just RAM. I was talking to Tridge the other day, and he said someone had hacked up something in userspace which kinda worked ... I'll get some details.
I view UP -> SMP -> NUMA -> SSI on NUMA -> SSI on many PCs -> beowulf cluster as a continuum ... the SSI problems are easier on NUMA, because you can wimp out on things like shmem much easier, but it's all similar.
M.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |