On Tue, 2006-03-28 at 12:21 -0500, Martin Hicks wrote: > On Tue, Mar 28, 2006 at 11:27:08AM -0500, Peter Sjoberg wrote: > > I just wonder if anyone knows what state the linux NUMA implementation > > is at. I looked on some linux numa sites but it seems very dated (many > > 2001 and 2004 the latest). > > I had a discussion with a friend about how good numa is on linux and his > > opinion is that we should run x86 Solaris on all opterons or replace the > > 4way with UP system since numa is so immature under linux. > > NUMA works quite well under Linux. There is room for improvement, > perhaps, but people like HP, AMD and SGI all have NUMA machines, and > SGI's are even Linux *only* (and they're actually the biggest computers > too, with up to 1024CPUs in a single machine) I'm interested in how far it goes. As I understand it you have some stickiness when it comes to process cpu but don't know how strong it is. If a process starts to access a file, are the cache buffers allocated randomly or going to the same cpu(socket). Is memory migration planned? I seen some talk about making it more aware about near -far-farther memory, and make it work better with multi-core and multi threading. Solaris has implemented at least some of it in the latest version (to work better with there 8 core 32 thread cpu). Where does Linux kernel stand on this? Where is the best place to ask this questions? Didn't see linux-numa and in linux-kernel with 300+ mails/day is more then I handle. > > There is libNUMA to do manual intervention on how you want memory > policies to be inforced (local first, round robin, local only) as well > as assigning jobs to run on certain CPUs. Guess that works for program written for it but what about normal cases. I have an almost hypothetical case with 4 cpu/memory hogging java processes running on a 4way opteron. Almost since the case exist but they run Redhat 4 -32bit so the OS can't handle numa and they aren't interested in moving to -64bit(yet). > > mh >