On Fri, Jun 26, 2015 at 06:09:05PM +0800, Xishi Qiu wrote: > memmap_init_zone() > ... > if ((z->zone_start_pfn <= pfn) > && (pfn < zone_end_pfn(z)) > && !(pfn & (pageblock_nr_pages - 1))) > set_pageblock_migratetype(page, MIGRATE_MOVABLE); > ... > > If the pfn does not align to pageblock, it will not init the migratetype. What important impact does that have? It should leave a partial pageblock as MIGRATE_UNMOVABLE which is fine by me. > So call it for every page, it will takes more time, but it doesn't matter, > this function will be called only in boot or hotadd memory. > It's a lot of additional overhead to add to memory initialisation. It would need to be for an excellent reason with no alternative solution. -- Mel Gorman SUSE Labs -- 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>