Hello, This patch set tweaks compaction and makes it possible to trigger pool compaction automatically when system is getting low on memory.
zsmalloc in some cases can suffer from a notable fragmentation and compaction can release some considerable amount of memory. The problem here is that currently we fully rely on user space to perform compaction when needed. However, performing zsmalloc compaction is not always an obvious thing to do. For example, suppose we have a `idle' fragmented (compaction was never performed) zram device and system is getting low on memory due to some 3rd party user processes (gcc LTO, or firefox, etc.). It's quite unlikely that user space will issue zpool compaction in this case. Besides, user space cannot tell for sure how badly pool is fragmented; however, this info is known to zsmalloc and, hence, to a shrinker. v2: -- use a slab shrinker instead of triggering compaction from zs_free (Minchan) Sergey Senozhatsky (8): zsmalloc: drop unused variable `nr_to_migrate' zsmalloc: partial page ordering within a fullness_list zsmalloc: lower ZS_ALMOST_FULL waterline zsmalloc: always keep per-class stats zsmalloc: introduce zs_can_compact() function zsmalloc: cosmetic compaction code adjustments zsmalloc/zram: move `num_migrated' to zs_pool zsmalloc: register a shrinker to trigger auto-compaction drivers/block/zram/zram_drv.c | 12 +-- drivers/block/zram/zram_drv.h | 1 - include/linux/zsmalloc.h | 1 + mm/zsmalloc.c | 228 +++++++++++++++++++++++++++--------------- 4 files changed, 152 insertions(+), 90 deletions(-) -- 2.4.2.387.gf86f31a -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
