2016-02-15 19:06 GMT+09:00 Xishi Qiu <qiuxishi@xxxxxxxxxx>: > On 2016/2/15 10:42, Joonsoo Kim wrote: > >>> >>> I have a question about the zone continuity. because hole exists at >>> arbitrary position in a page block. Therefore, only pageblock_pf_to_page() >>> is insufficiency, whether pageblock aligned pfn or not , the pfn_valid_within() >>> is necessary. >>> >>> eh: 120M-122M is a range of page block, but the 120.5M-121.5M is holes, only by >>> pageblock_pfn_to_page() to conclude in the result is inaccurate >> >> contiguous may be misleading word. It doesn't represent there are no >> hole. It only represents that all pageblocks within zone span belong to >> corresponding zone and validity of all pageblock aligned pfn is >> checked. So, if it is set, we can safely call pfn_to_page() for pageblock >> aligned pfn in that zone without checking pfn_valid(). >> >> Thanks. >> > > Hi Joonsoo, > > So "contiguous" here only means that struct page is exist, and don't care whether > the memory is exist, right? Yes. 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>