On 08/13/2013 12:46 AM, Tejun Heo wrote: ......
* Adding an option to tell the kernel to try to stay away from hotpluggable nodes is fine. I have no problem with that at all. * The patchsets upto this point have been somehow trying to reorder operations shomehow such that *no* memory allocation happens before memblock is populated with hotplug information. * However, we already *know* that the memory the kernel image is occupying won't be removeable. It's highly likely that the amount of memory allocation before NUMA / hotplug information is fully populated is pretty small. Also, it's highly likely that small amount of memory right after the kernel image is contained in the same NUMA node, so if we allocate memory close to the kernel image, it's likely that we don't contaminate hotpluggable node. We're talking about few megs at most right after the kernel image. I can't see how that would make any noticeable difference. * Once hotplug information is available, allocation can happen as usual and the kernel can report the nodes which are actually hotpluggable - marked as hotpluggable by the firmware&& didn't get contaminated during early alloc&& didn't get overflow allocations afterwards. Note that we need such mechanism no matter what as the kernel image can be loaded into hotpluggable nodes and reporting that to userland is the only thing the kernel can do for cases like that short of denying memory unplug on such nodes.
Hi tj, hpa, luck, yinghai, So if all of you agree on the idea above from tj, I think we can do it in this way. Will update the patches to allocate memory near kernel image before SRAT is parsed. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>