Hi, Currently zbud pages are not movable and they cannot be allocated from CMA region. These patches try to address the problem by: 1. Adding a new form of reclaim of zbud pages. 2. Reclaiming zbud pages during migration and compaction. 3. Allocating zbud pages with __GFP_RECLAIMABLE flag. This reclaim process is different than zbud_reclaim_page(). It acts more like swapoff() by trying to unuse pages stored in zbud page and bring them back to memory. The standard zbud_reclaim_page() on the other hand tries to write them back. One of patches introduces PageZbud() function which identifies zbud pages my page->_mapcount. Dave Hansen proposed aliasing PG_zbud=PG_slab but in such case patch would be more intrusive. Any ideas for a better solution are welcome. TODO-s: 1. Migrate zbud pages directly instead of reclaiming. Changes since v1: 1. Rebased against v3.11-rc4-103-g6c2580c. 2. Remove rebalance_lists() to fix reinserting zbud page after zbud_free. This function was added because similar code was present in zbud_free/zbud_alloc/zbud_reclaim_page but it turns out that there is no benefit in generalizing this code. (suggested by Seth Jennings) 3. Remove BUG_ON checks for first/last chunks during free and reclaim. (suggested by Seth Jennings) 4. Use page->_mapcount==-127 instead of new PG_zbud flag. (suggested by Dave Hansen) 5. Fix invalid dereference of pointer to compact_control in page_alloc.c. 6. Fix lost return value in try_to_unuse() in swapfile.c (this fixes hang when swapoff was interrupted e.g. by CTRL+C). Best regards, Krzysztof Kozlowski Krzysztof Kozlowski (4): zbud: use page ref counter for zbud pages mm: split code for unusing swap entries from try_to_unuse mm: use mapcount for identifying zbud pages mm: reclaim zbud pages on migration and compaction include/linux/mm.h | 23 +++ include/linux/swapfile.h | 2 + include/linux/zbud.h | 11 +- mm/compaction.c | 20 ++- mm/internal.h | 1 + mm/page_alloc.c | 6 + mm/swapfile.c | 356 ++++++++++++++++++++++++---------------------- mm/zbud.c | 247 +++++++++++++++++++++++--------- mm/zswap.c | 57 +++++++- 9 files changed, 476 insertions(+), 247 deletions(-) -- 1.7.9.5 -- 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>