Kumar Gala wrote: > > On Dec 7, 2007, at 3:35 PM, Balbir Singh wrote: > >> Olof Johansson wrote: >>> Hi, >>> >>> On Sat, Dec 08, 2007 at 02:44:25AM +0530, Balbir Singh wrote: >>> >>>> Comments are as always welcome! >>> >>> Care to explain what this is useful for? (Not saying it's a stupid idea, >>> just wondering what the reason for doing it is). >>> >> >> In my case, I use it to test parts of my memory controller patches on an >> emulated NUMA machine. I plan to use it to test out page migration >> across nodes. > > Can you explain that further. I'm still not clear on why this is useful. > > - k
Sure. In my case I need to emulate NUMA nodes to do some NUMA specific testing. The memory controller I've written has some interesting data structures like per node, per zone LRU lists. To be able to test those features on a non-numa box is a problem, since we get just the default node. To be able to test the memory controller under NUMA, I use fake NUMA nodes. x86-64 has a similar feature, the code I have here is the simplest I could come up with for PowerPC. I just thought of another very interesting use case, it can be used to split up the zone's lru lock which is highly contended. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev