Hi, this is an updated version. No major changes from the last one except for page allocation function. removed RFC. Order of patches is [1/4] move some functions from memory_hotplug.c to page_isolation.c [2/4] search physically contiguous range suitable for big chunk alloc. [3/4] allocate big chunk memory based on memory hotplug(migration) technique [4/4] modify page allocation function. For what: I hear there is requirements to allocate a chunk of page which is larger than MAX_ORDER. Now, some (embeded) device use a big memory chunk. To use memory, they hide some memory range by boot option (mem=) and use hidden memory for its own purpose. But this seems a lack of feature in memory management. This patch adds alloc_contig_pages(start, end, nr_pages, gfp_mask) to allocate a chunk of page whose length is nr_pages from [start, end) phys address. This uses similar logic of memory-unplug, which tries to offline [start, end) pages. By this, drivers can allocate 30M or 128M or much bigger memory chunk on demand. (I allocated 1G chunk in my test). But yes, because of fragmentation, this cannot guarantee 100% alloc. If alloc_contig_pages() is called in system boot up or movable_zone is used, this allocation succeeds at high rate. I tested this on x86-64, and it seems to work as expected. But feedback from embeded guys are appreciated because I think they are main user of this function. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>