On Tue, 21 Mar 2006 10:00:12 -0800 Dave Hansen <haveblue@xxxxxxxxxx> wrote: > On Sat, 2006-03-18 at 10:26 +0900, KAMEZAWA Hiroyuki wrote: > > If *determine node* function is moved to arch specific parts, > > memory hot add need more and more codes to determine paddr -> nid in arch > > specific codes. Then, we have to add new paddr->nid function even if new nid is > > passed by firmware. We *lose* useful information of nid from firmware if > > add_memory() has just 2 args, (start, end). > > What I'm saying is that I'd like add_memory() to be just that, for > adding memory. > > At some point in the process, you need to export the NUMA node layout to > the rest of the system, to say which pages go in which node. I'm just > saying that you should do that _before_ add_memory(). > To do so, we have to maintain new pfn_to_nid() function. We have to maintain a new table/list and have to consider name of it :). And, add_memory() has to check whether a node which belongs exists ot not, again. I don't want these kind of things. With current kernel, we have to add new *pgdat* to node when adding a new node. (If we don't, the kernel goes panic()) And we have to allocate a pgdat/zones in a local node in future. So adding a node before adding memory is not good. (current code uses kmalloc() just for reducing complexity.) > add_memory() should support adding memory to more than one node. If any > hypervisor or hardware happens to have memory added in one contiguous > chunk, it can not simply call add_memory(). _That_ firmware would be > forced to do the NUMA parsing and figure out how many times to call > add_memory(). I don't think the firmware adds memory of multiple nodes at once. It's crazy. > > Let me reiterate: the process of telling the system which pages are in > which node should be separate from telling the system that there *are* > currently pages there now. Considering "cpu only node', "check and add new node" function can be separated, like add_memory_less_node().(But pgdat/zone etc.. will be allocated in out of node.) Bye. -- Kame - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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