On Wed, Nov 17, 2010 at 01:18:50PM -0800, David Rientjes wrote: > On Wed, 17 Nov 2010, Dave Hansen wrote: > > > The other thing that Greg suggested was to use configfs. Looking back > > on it, that makes a lot of sense. We can do better than these "probe" > > files. > > > > In your case, it might be useful to tell the kernel to be able to add > > memory in a node and add the node all in one go. That'll probably be > > closer to what the hardware will do, and will exercise different code > > paths that the separate "add node", "then add memory" steps that you're > > using here. > > > > That seems like a seperate issue of moving the memory hotplug interface > over to configfs and that seems like it will cause a lot of userspace > breakage. The memory hotplug interface can already add memory to a node > without using the ACPI notifier, so what does it have to do with this > patchset? Agree with you, I do not suggest to implement it in this patchset. > > I think what this patchset really wants to do is map offline hot-added > memory to a different node id before it is onlined. It needs no > additional command-line interface or kconfig options, users just need to > physically hot-add memory at runtime or use mem= when booting to reserve > present memory from being used. I already send out the implementation in another email, you can help to do a review. > > Then, export the amount of memory that is actually physically present in > the e820 but was truncated by mem= and allow users to hot-add the memory > via the probe interface. Add a writeable 'node' file to offlined memory > section directories and allow it to be changed prior to online. for memory offlining, it is a known diffcult thing, and it is not supported well in current kernel, so I do not suggest to provide the offline interface in the emulator, it just take more pains. We can consider to add it when the memory offlining works well. -- Thanks & Regards, Shaohui -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>