Recently, I got many reports about perfermance degradation in embedded system(Android mobile phone, webOS TV and so on) and failed to fork easily. The problem was fragmentation caused by zram and GPU driver pages. Their pages cannot be migrated so compaction cannot work well, either so reclaimer ends up shrinking all of working set pages. It made system very slow and even to fail to fork easily. Other pain point is that they cannot work with CMA. Most of CMA memory space could be idle(ie, it could be used for movable pages unless driver is using) but if driver(i.e., zram) cannot migrate his page, that memory space could be wasted. In our product which has big CMA memory, it reclaims zones too exccessively although there are lots of free space in CMA so system was very slow easily. To solve these problem, this patch try to add facility to migrate non-lru pages via introducing new friend functions of migratepage in address_space_operation and new page flags. (isolate_page, putback_page) (PG_movable, PG_isolated) For details, please read description in "mm/compaction: support non-lru movable page migration". Originally, Gioh Kim tried to support this feature but he moved so I took over the work. But I took many code from his work and changed a little bit. Thanks, Gioh! And I should mention Konstantin Khlebnikov. He really heped Gioh at that time so he should deserve to have many credit, too. Thanks, Konstantin! This patchset consists of five parts. 1. clean up migration mm: use put_page to free page instead of putback_lru_page 2. add non-lru page migration feature mm/compaction: support non-lru movable page migration mm: add non-lru movable page support document 3. rework KVM memory-ballooning mm/balloon: use general movable page feature into balloon 4. zsmalloc clean-up for preparing page migration zsmalloc: keep max_object in size_class zsmalloc: squeeze inuse into page->mapping zsmalloc: remove page_mapcount_reset zsmalloc: squeeze freelist into page->mapping zsmalloc: move struct zs_meta from mapping to freelist zsmalloc: factor page chain functionality out zsmalloc: separate free_zspage from putback_zspage zsmalloc: zs_compact refactoring 5. add zsmalloc page migration zsmalloc: migrate head page of zspage zsmalloc: use single linked list for page chain zsmalloc: migrate tail pages in zspage zram: use __GFP_MOVABLE for memory allocation * From v2 * rebase on mmotm-2016-03-29-15-54-16 * check PageMovable before lock_page - Joonsoo * check PageMovable before PageIsolated checking - Joonsoo * add more description about rule * From v1 * rebase on v4.5-mmotm-2016-03-17-15-04 * reordering patches to merge clean-up patches first * add Acked-by/Reviewed-by from Vlastimil and Sergey * use each own mount model instead of reusing anon_inode_fs - Al Viro * small changes - YiPing, Gioh Minchan Kim (16): mm: use put_page to free page instead of putback_lru_page mm/compaction: support non-lru movable page migration mm: add non-lru movable page support document mm/balloon: use general movable page feature into balloon zsmalloc: keep max_object in size_class zsmalloc: squeeze inuse into page->mapping zsmalloc: remove page_mapcount_reset zsmalloc: squeeze freelist into page->mapping zsmalloc: move struct zs_meta from mapping to freelist zsmalloc: factor page chain functionality out zsmalloc: separate free_zspage from putback_zspage zsmalloc: zs_compact refactoring zsmalloc: migrate head page of zspage zsmalloc: use single linked list for page chain zsmalloc: migrate tail pages in zspage zram: use __GFP_MOVABLE for memory allocation Documentation/filesystems/Locking | 4 + Documentation/filesystems/vfs.txt | 16 +- Documentation/vm/page_migration | 69 +- drivers/block/zram/zram_drv.c | 3 +- drivers/virtio/virtio_balloon.c | 53 +- fs/proc/page.c | 3 + include/linux/balloon_compaction.h | 49 +- include/linux/fs.h | 2 + include/linux/migrate.h | 2 + include/linux/page-flags.h | 47 +- include/uapi/linux/kernel-page-flags.h | 1 + include/uapi/linux/magic.h | 2 + mm/balloon_compaction.c | 101 +-- mm/compaction.c | 15 +- mm/migrate.c | 238 ++++-- mm/vmscan.c | 2 +- mm/zsmalloc.c | 1253 ++++++++++++++++++++++++-------- 17 files changed, 1368 insertions(+), 492 deletions(-) -- 1.9.1 -- 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>