On Sun, Jun 8, 2014 at 3:14 PM, Luiz Capitulino <lcapitulino@xxxxxxxxxx> wrote: > In short, I believe this is just dead code for the upstream kernel but this > causes a bug for 2.6.32 based kernels. > > The setup_node_data() function is used to initialize NODE_DATA() for a node. > It gets a node id and a memory range. The start address for the memory range > is rounded up to ZONE_ALIGN and then it's used to initialize > NODE_DATA(nid)->node_start_pfn. > The 2.6.32 kernel did use the rounded up range start to register a node's > memory range with the bootmem interface by calling init_bootmem_node(). > A few steps later during bootmem initialization, the 2.6.32 kernel calls > free_bootmem_with_active_regions() to initialize the bootmem bitmap. This > function goes through all memory ranges read from the SRAT table and try > to mark them as usable for bootmem usage. However, before marking a range > as usable, mark_bootmem_node() asserts if the memory range start address > (as read from the SRAT table) is less than the value registered with > init_bootmem_node(). The assertion will trigger whenever the memory range > start address is rounded up, as it will always be greater than what is > reported in the SRAT table. This is true when the 2.6.32 kernel runs as a > HyperV guest on Windows Server 2012. Dropping ZONE_ALIGN solves the > problem there. What is e820 memmap and srat from HyperV guest? Can you post bootlog first 200 lines? Thanks Yinghai -- 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>