On Thu, Mar 26, 2015 at 06:16:22AM +0900, Gioh Kim wrote: > > > 2015-03-25 ?????? 7:56??? Mel Gorman ???(???) ??? ???: > >On Wed, Mar 25, 2015 at 11:39:15AM +0900, Gioh Kim wrote: > >>My driver allocates more than 40MB pages via alloc_page() at a time and > >>maps them at virtual address. Totally it uses 300~400MB pages. > >> > >>If I run a heavy load test for a few days in 1GB memory system, I cannot allocate even order=3 pages > >>because-of the external fragmentation. > >> > >>I thought I needed a anti-fragmentation solution for my driver. > >>But there is no allocation function that considers fragmentation. > >>The compaction is not helpful because it is only for movable pages, not unmovable pages. > >> > >>This patch proposes a allocation function allocates only pages in the same pageblock. > >> > > > >Is this not what CMA is for? Or creating a MOVABLE zone? > > It's not related to CMA and MOVABLE zone. > It's for compaction and anti-fragmentation for any zone. > Create a CMA area, allow your driver to use it use alloc_contig_range. As it is, this is creating another contiguous range allocation function with no in-kernel users. -- 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>