Hi, This is third version of patches adding migration of zbud pages with changes after discussions with Seth: http://article.gmane.org/gmane.linux.kernel.mm/107695 In patch [PATCH 5/6] I removed the red-black tree in zswap and instead added a radix tree in zbud. This also lead to removal of the "handle" concept and to usage of offset as radix tree's index. This particular change (5/6) still needs some improvements: 1. Accept storing of duplicated pages (as it was in original zswap). 2. Use RCU for radix tree reads and updates. 3. Optimize locking in zbud_free_all(). 4. Iterate over LRU list instead of radix tree in zbud_free_all(). Description of patches: ----------------- Currently zbud pages are not movable and they cannot be allocated from CMA (Contiguous Memory Allocator) region. These patches add migration of zbud pages. The zbud migration code utilizes mapping so many exceptions to migrate code were added. This can be replaced for example with pin page control subsystem: http://article.gmane.org/gmane.linux.kernel.mm/105308 In such case the zbud migration code (zbud_migrate_page()) can be safely re-used. * [PATCH 1/6] adds a reference counter to zbud pages. * [PATCH 2/6] is a trivial change of scope of local variable. * [PATCH 3/6] introduces PageZbud() function which identifies zbud pages by 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. * [PATCH 4/6] replaces direct initialization of zbud_header with memset. * [PATCH 5/6] replaces zswap's red-black tree with a new radix tree in zbud. Offset is used as index to this tree. * [PATCH 6/6] implements migration of zbud pages. This patch set is based on v3.12-rc4-19-g8b5ede6. Changes since v2: ----------------- 1. Rebased against v3.12-rc4-19-g8b5ede6. 2. Replace zswap's red-black tree with a new radix tree in zbud. Use offset as tree's index. Many zbud API changes. 3. Add patch 4/6. Changes since v1: ----------------- 1. Rebased against v3.11. 2. Updated documentation of zbud_reclaim_page() to match usage of zbud page reference counters. 3. Split from patch 2/4 trivial change of scope of freechunks var to separate patch (3/5) (suggested by Seth Jennings). Best regards, Krzysztof Kozlowski Krzysztof Kozlowski (6): zbud: use page ref counter for zbud pages zbud: make freechunks a block local variable mm: use mapcount for identifying zbud pages zbud: memset zbud_header to 0 during init zswap: replace tree in zswap with radix tree in zbud mm: migrate zbud pages include/linux/mm.h | 23 ++ include/linux/zbud.h | 28 ++- mm/compaction.c | 7 + mm/migrate.c | 17 +- mm/zbud.c | 644 +++++++++++++++++++++++++++++++++++++++----------- mm/zswap.c | 419 ++++++-------------------------- 6 files changed, 643 insertions(+), 495 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>