On 2014/8/16 21:04, Tejun Heo wrote: > On Mon, Aug 11, 2014 at 09:31:22PM +0800, Xishi Qiu wrote: >> Let memblock skip the hotpluggable memory regions in __next_mem_range(), >> it is used to to prevent memblock from allocating hotpluggable memory >> for the kernel at early time. The code is the same as __next_mem_range_rev(). >> >> Clear hotpluggable flag before releasing free pages to the buddy allocator. > > Please try to explain "why" in addition to "what". Why do we need to > clear hotpluggable flag in free_low_memory_core_early() in addition to > numa_clear_node_hotplug() in x86 numa.c? Does this make x86 code > redundant? If not, why? > Hi Tejun, numa_clear_node_hotplug()? There is only numa_clear_kernel_node_hotplug(). If we don't clear hotpluggable flag in free_low_memory_core_early(), the memory which marked hotpluggable flag will not free to buddy allocator. Because __next_mem_range() will skip them. free_low_memory_core_early for_each_free_mem_range for_each_mem_range __next_mem_range Thanks, Xishi Qiu -- 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>