Hello andrew, On 10/04/2013 04:42 AM, Andrew Morton wrote: > On Thu, 03 Oct 2013 11:32:02 +0800 Zhang Yanfei <zhangyanfei.yes@xxxxxxxxx> wrote: > >> We pass the number of pages which hold page structs of a memory >> section to function free_map_bootmem. This is right when >> !CONFIG_SPARSEMEM_VMEMMAP but wrong when CONFIG_SPARSEMEM_VMEMMAP. >> When CONFIG_SPARSEMEM_VMEMMAP, we should pass the number of pages >> of a memory section to free_map_bootmem. >> >> So the fix is removing the nr_pages parameter. When >> CONFIG_SPARSEMEM_VMEMMAP, we directly use the prefined marco >> PAGES_PER_SECTION in free_map_bootmem. When !CONFIG_SPARSEMEM_VMEMMAP, >> we calculate page numbers needed to hold the page structs for a >> memory section and use the value in free_map_bootmem. > > What were the runtime user-visible effects of that bug? > > Please always include this information when fixing a bug. Sorry....This was found by reading the code. And I have no machine that support memory hot-remove to test the bug now. But I believe it is a bug. BTW, I've made a mistake in this patch which was found by wanpeng. I'll send v2. -- Thanks. Zhang Yanfei -- 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>